view liboctave/array/CMatrix.cc @ 30564:796f54d4ddbf stable

update Octave Project Developers copyright for the new year In files that have the "Octave Project Developers" copyright notice, update for 2021. In all .txi and .texi files except gpl.txi and gpl.texi in the doc/liboctave and doc/interpreter directories, change the copyright to "Octave Project Developers", the same as used for other source files. Update copyright notices for 2022 (not done since 2019). For gpl.txi and gpl.texi, change the copyright notice to be "Free Software Foundation, Inc." and leave the date at 2007 only because this file only contains the text of the GPL, not anything created by the Octave Project Developers. Add Paul Thomas to contributors.in.
author John W. Eaton <jwe@octave.org>
date Tue, 28 Dec 2021 18:22:40 -0500
parents 117ebe363f56
children ec973756cb3a
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////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 1994-2022 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <algorithm>
#include <complex>
#include <istream>
#include <limits>
#include <ostream>

#include "Array-util.h"
#include "CDiagMatrix.h"
#include "CMatrix.h"
#include "CNDArray.h"
#include "CRowVector.h"
#include "DET.h"
#include "boolMatrix.h"
#include "chMatrix.h"
#include "chol.h"
#include "dDiagMatrix.h"
#include "dMatrix.h"
#include "dRowVector.h"
#include "lo-blas-proto.h"
#include "lo-error.h"
#include "lo-ieee.h"
#include "lo-lapack-proto.h"
#include "lo-mappers.h"
#include "lo-utils.h"
#include "mx-cm-dm.h"
#include "mx-cm-s.h"
#include "mx-dm-cm.h"
#include "mx-inlines.cc"
#include "mx-op-defs.h"
#include "oct-cmplx.h"
#include "oct-fftw.h"
#include "oct-locbuf.h"
#include "oct-norm.h"
#include "schur.h"
#include "svd.h"

static const Complex Complex_NaN_result (octave::numeric_limits<double>::NaN (),
                                         octave::numeric_limits<double>::NaN ());

// Complex Matrix class

ComplexMatrix::ComplexMatrix (const Matrix& a)
  : ComplexNDArray (a)
{ }

ComplexMatrix::ComplexMatrix (const RowVector& rv)
  : ComplexNDArray (rv)
{ }

ComplexMatrix::ComplexMatrix (const ColumnVector& cv)
  : ComplexNDArray (cv)
{ }

ComplexMatrix::ComplexMatrix (const DiagMatrix& a)
  : ComplexNDArray (a.dims (), 0.0)
{
  for (octave_idx_type i = 0; i < a.length (); i++)
    elem (i, i) = a.elem (i, i);
}

ComplexMatrix::ComplexMatrix (const MDiagArray2<double>& a)
  : ComplexNDArray (a.dims (), 0.0)
{
  for (octave_idx_type i = 0; i < a.length (); i++)
    elem (i, i) = a.elem (i, i);
}

ComplexMatrix::ComplexMatrix (const DiagArray2<double>& a)
  : ComplexNDArray (a.dims (), 0.0)
{
  for (octave_idx_type i = 0; i < a.length (); i++)
    elem (i, i) = a.elem (i, i);
}

ComplexMatrix::ComplexMatrix (const ComplexRowVector& rv)
  : ComplexNDArray (rv)
{ }

ComplexMatrix::ComplexMatrix (const ComplexColumnVector& cv)
  : ComplexNDArray (cv)
{ }

ComplexMatrix::ComplexMatrix (const ComplexDiagMatrix& a)
  : ComplexNDArray (a.dims (), 0.0)
{
  for (octave_idx_type i = 0; i < a.length (); i++)
    elem (i, i) = a.elem (i, i);
}

ComplexMatrix::ComplexMatrix (const MDiagArray2<Complex>& a)
  : ComplexNDArray (a.dims (), 0.0)
{
  for (octave_idx_type i = 0; i < a.length (); i++)
    elem (i, i) = a.elem (i, i);
}

ComplexMatrix::ComplexMatrix (const DiagArray2<Complex>& a)
  : ComplexNDArray (a.dims (), 0.0)
{
  for (octave_idx_type i = 0; i < a.length (); i++)
    elem (i, i) = a.elem (i, i);
}

// FIXME: could we use a templated mixed-type copy function here?

ComplexMatrix::ComplexMatrix (const boolMatrix& a)
  : ComplexNDArray (a)
{ }

ComplexMatrix::ComplexMatrix (const charMatrix& a)
  : ComplexNDArray (a.dims (), 0.0)
{
  for (octave_idx_type i = 0; i < a.rows (); i++)
    for (octave_idx_type j = 0; j < a.cols (); j++)
      elem (i, j) = static_cast<unsigned char> (a.elem (i, j));
}

ComplexMatrix::ComplexMatrix (const Matrix& re, const Matrix& im)
  : ComplexNDArray (re.dims ())
{
  if (im.rows () != rows () || im.cols () != cols ())
    (*current_liboctave_error_handler) ("complex: internal error");

  octave_idx_type nel = numel ();
  for (octave_idx_type i = 0; i < nel; i++)
    xelem (i) = Complex (re(i), im(i));
}

bool
ComplexMatrix::operator == (const ComplexMatrix& a) const
{
  if (rows () != a.rows () || cols () != a.cols ())
    return false;

  return mx_inline_equal (numel (), data (), a.data ());
}

bool
ComplexMatrix::operator != (const ComplexMatrix& a) const
{
  return !(*this == a);
}

bool
ComplexMatrix::ishermitian (void) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (issquare () && nr > 0)
    {
      for (octave_idx_type i = 0; i < nr; i++)
        for (octave_idx_type j = i; j < nc; j++)
          if (elem (i, j) != conj (elem (j, i)))
            return false;

      return true;
    }

  return false;
}

// destructive insert/delete/reorder operations

ComplexMatrix&
ComplexMatrix::insert (const Matrix& a, octave_idx_type r, octave_idx_type c)
{
  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (r < 0 || r + a_nr > rows () || c < 0 || c + a_nc > cols ())
    (*current_liboctave_error_handler) ("range error for insert");

  if (a_nr >0 && a_nc > 0)
    {
      make_unique ();

      for (octave_idx_type j = 0; j < a_nc; j++)
        for (octave_idx_type i = 0; i < a_nr; i++)
          xelem (r+i, c+j) = a.elem (i, j);
    }

  return *this;
}

ComplexMatrix&
ComplexMatrix::insert (const RowVector& a, octave_idx_type r, octave_idx_type c)
{
  octave_idx_type a_len = a.numel ();

  if (r < 0 || r >= rows () || c < 0 || c + a_len > cols ())
    (*current_liboctave_error_handler) ("range error for insert");

  if (a_len > 0)
    {
      make_unique ();

      for (octave_idx_type i = 0; i < a_len; i++)
        xelem (r, c+i) = a.elem (i);
    }

  return *this;
}

ComplexMatrix&
ComplexMatrix::insert (const ColumnVector& a,
                       octave_idx_type r, octave_idx_type c)
{
  octave_idx_type a_len = a.numel ();

  if (r < 0 || r + a_len > rows () || c < 0 || c >= cols ())
    (*current_liboctave_error_handler) ("range error for insert");

  if (a_len > 0)
    {
      make_unique ();

      for (octave_idx_type i = 0; i < a_len; i++)
        xelem (r+i, c) = a.elem (i);
    }

  return *this;
}

ComplexMatrix&
ComplexMatrix::insert (const DiagMatrix& a,
                       octave_idx_type r, octave_idx_type c)
{
  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (r < 0 || r + a_nr > rows () || c < 0 || c + a_nc > cols ())
    (*current_liboctave_error_handler) ("range error for insert");

  fill (0.0, r, c, r + a_nr - 1, c + a_nc - 1);

  octave_idx_type a_len = a.length ();

  if (a_len > 0)
    {
      make_unique ();

      for (octave_idx_type i = 0; i < a_len; i++)
        xelem (r+i, c+i) = a.elem (i, i);
    }

  return *this;
}

ComplexMatrix&
ComplexMatrix::insert (const ComplexMatrix& a,
                       octave_idx_type r, octave_idx_type c)
{
  ComplexNDArray::insert (a, r, c);
  return *this;
}

ComplexMatrix&
ComplexMatrix::insert (const ComplexRowVector& a,
                       octave_idx_type r, octave_idx_type c)
{
  octave_idx_type a_len = a.numel ();
  if (r < 0 || r >= rows () || c < 0 || c + a_len > cols ())
    (*current_liboctave_error_handler) ("range error for insert");

  for (octave_idx_type i = 0; i < a_len; i++)
    elem (r, c+i) = a.elem (i);

  return *this;
}

ComplexMatrix&
ComplexMatrix::insert (const ComplexColumnVector& a,
                       octave_idx_type r, octave_idx_type c)
{
  octave_idx_type a_len = a.numel ();

  if (r < 0 || r + a_len > rows () || c < 0 || c >= cols ())
    (*current_liboctave_error_handler) ("range error for insert");

  if (a_len > 0)
    {
      make_unique ();

      for (octave_idx_type i = 0; i < a_len; i++)
        xelem (r+i, c) = a.elem (i);
    }

  return *this;
}

ComplexMatrix&
ComplexMatrix::insert (const ComplexDiagMatrix& a,
                       octave_idx_type r, octave_idx_type c)
{
  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (r < 0 || r + a_nr > rows () || c < 0 || c + a_nc > cols ())
    (*current_liboctave_error_handler) ("range error for insert");

  fill (0.0, r, c, r + a_nr - 1, c + a_nc - 1);

  octave_idx_type a_len = a.length ();

  if (a_len > 0)
    {
      make_unique ();

      for (octave_idx_type i = 0; i < a_len; i++)
        xelem (r+i, c+i) = a.elem (i, i);
    }

  return *this;
}

ComplexMatrix&
ComplexMatrix::fill (double val)
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (nr > 0 && nc > 0)
    {
      make_unique ();

      for (octave_idx_type j = 0; j < nc; j++)
        for (octave_idx_type i = 0; i < nr; i++)
          xelem (i, j) = val;
    }

  return *this;
}

ComplexMatrix&
ComplexMatrix::fill (const Complex& val)
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (nr > 0 && nc > 0)
    {
      make_unique ();

      for (octave_idx_type j = 0; j < nc; j++)
        for (octave_idx_type i = 0; i < nr; i++)
          xelem (i, j) = val;
    }

  return *this;
}

ComplexMatrix&
ComplexMatrix::fill (double val, octave_idx_type r1, octave_idx_type c1,
                     octave_idx_type r2, octave_idx_type c2)
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (r1 < 0 || r2 < 0 || c1 < 0 || c2 < 0
      || r1 >= nr || r2 >= nr || c1 >= nc || c2 >= nc)
    (*current_liboctave_error_handler) ("range error for fill");

  if (r1 > r2) { std::swap (r1, r2); }
  if (c1 > c2) { std::swap (c1, c2); }

  if (r2 >= r1 && c2 >= c1)
    {
      make_unique ();

      for (octave_idx_type j = c1; j <= c2; j++)
        for (octave_idx_type i = r1; i <= r2; i++)
          xelem (i, j) = val;
    }

  return *this;
}

ComplexMatrix&
ComplexMatrix::fill (const Complex& val, octave_idx_type r1, octave_idx_type c1,
                     octave_idx_type r2, octave_idx_type c2)
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (r1 < 0 || r2 < 0 || c1 < 0 || c2 < 0
      || r1 >= nr || r2 >= nr || c1 >= nc || c2 >= nc)
    (*current_liboctave_error_handler) ("range error for fill");

  if (r1 > r2) { std::swap (r1, r2); }
  if (c1 > c2) { std::swap (c1, c2); }

  if (r2 >= r1 && c2 >=c1)
    {
      make_unique ();

      for (octave_idx_type j = c1; j <= c2; j++)
        for (octave_idx_type i = r1; i <= r2; i++)
          xelem (i, j) = val;
    }

  return *this;
}

ComplexMatrix
ComplexMatrix::append (const Matrix& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nr != a.rows ())
    (*current_liboctave_error_handler) ("row dimension mismatch for append");

  octave_idx_type nc_insert = nc;
  ComplexMatrix retval (nr, nc + a.cols ());
  retval.insert (*this, 0, 0);
  retval.insert (a, 0, nc_insert);
  return retval;
}

ComplexMatrix
ComplexMatrix::append (const RowVector& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nr != 1)
    (*current_liboctave_error_handler) ("row dimension mismatch for append");

  octave_idx_type nc_insert = nc;
  ComplexMatrix retval (nr, nc + a.numel ());
  retval.insert (*this, 0, 0);
  retval.insert (a, 0, nc_insert);
  return retval;
}

ComplexMatrix
ComplexMatrix::append (const ColumnVector& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nr != a.numel ())
    (*current_liboctave_error_handler) ("row dimension mismatch for append");

  octave_idx_type nc_insert = nc;
  ComplexMatrix retval (nr, nc + 1);
  retval.insert (*this, 0, 0);
  retval.insert (a, 0, nc_insert);
  return retval;
}

ComplexMatrix
ComplexMatrix::append (const DiagMatrix& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nr != a.rows ())
    (*current_liboctave_error_handler) ("row dimension mismatch for append");

  octave_idx_type nc_insert = nc;
  ComplexMatrix retval (nr, nc + a.cols ());
  retval.insert (*this, 0, 0);
  retval.insert (a, 0, nc_insert);
  return retval;
}

ComplexMatrix
ComplexMatrix::append (const ComplexMatrix& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nr != a.rows ())
    (*current_liboctave_error_handler) ("row dimension mismatch for append");

  octave_idx_type nc_insert = nc;
  ComplexMatrix retval (nr, nc + a.cols ());
  retval.insert (*this, 0, 0);
  retval.insert (a, 0, nc_insert);
  return retval;
}

ComplexMatrix
ComplexMatrix::append (const ComplexRowVector& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nr != 1)
    (*current_liboctave_error_handler) ("row dimension mismatch for append");

  octave_idx_type nc_insert = nc;
  ComplexMatrix retval (nr, nc + a.numel ());
  retval.insert (*this, 0, 0);
  retval.insert (a, 0, nc_insert);
  return retval;
}

ComplexMatrix
ComplexMatrix::append (const ComplexColumnVector& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nr != a.numel ())
    (*current_liboctave_error_handler) ("row dimension mismatch for append");

  octave_idx_type nc_insert = nc;
  ComplexMatrix retval (nr, nc + 1);
  retval.insert (*this, 0, 0);
  retval.insert (a, 0, nc_insert);
  return retval;
}

ComplexMatrix
ComplexMatrix::append (const ComplexDiagMatrix& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nr != a.rows ())
    (*current_liboctave_error_handler) ("row dimension mismatch for append");

  octave_idx_type nc_insert = nc;
  ComplexMatrix retval (nr, nc + a.cols ());
  retval.insert (*this, 0, 0);
  retval.insert (a, 0, nc_insert);
  return retval;
}

ComplexMatrix
ComplexMatrix::stack (const Matrix& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nc != a.cols ())
    (*current_liboctave_error_handler) ("column dimension mismatch for stack");

  octave_idx_type nr_insert = nr;
  ComplexMatrix retval (nr + a.rows (), nc);
  retval.insert (*this, 0, 0);
  retval.insert (a, nr_insert, 0);
  return retval;
}

ComplexMatrix
ComplexMatrix::stack (const RowVector& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nc != a.numel ())
    (*current_liboctave_error_handler) ("column dimension mismatch for stack");

  octave_idx_type nr_insert = nr;
  ComplexMatrix retval (nr + 1, nc);
  retval.insert (*this, 0, 0);
  retval.insert (a, nr_insert, 0);
  return retval;
}

ComplexMatrix
ComplexMatrix::stack (const ColumnVector& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nc != 1)
    (*current_liboctave_error_handler) ("column dimension mismatch for stack");

  octave_idx_type nr_insert = nr;
  ComplexMatrix retval (nr + a.numel (), nc);
  retval.insert (*this, 0, 0);
  retval.insert (a, nr_insert, 0);
  return retval;
}

ComplexMatrix
ComplexMatrix::stack (const DiagMatrix& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nc != a.cols ())
    (*current_liboctave_error_handler) ("column dimension mismatch for stack");

  octave_idx_type nr_insert = nr;
  ComplexMatrix retval (nr + a.rows (), nc);
  retval.insert (*this, 0, 0);
  retval.insert (a, nr_insert, 0);
  return retval;
}

ComplexMatrix
ComplexMatrix::stack (const ComplexMatrix& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nc != a.cols ())
    (*current_liboctave_error_handler) ("column dimension mismatch for stack");

  octave_idx_type nr_insert = nr;
  ComplexMatrix retval (nr + a.rows (), nc);
  retval.insert (*this, 0, 0);
  retval.insert (a, nr_insert, 0);
  return retval;
}

ComplexMatrix
ComplexMatrix::stack (const ComplexRowVector& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nc != a.numel ())
    (*current_liboctave_error_handler) ("column dimension mismatch for stack");

  octave_idx_type nr_insert = nr;
  ComplexMatrix retval (nr + 1, nc);
  retval.insert (*this, 0, 0);
  retval.insert (a, nr_insert, 0);
  return retval;
}

ComplexMatrix
ComplexMatrix::stack (const ComplexColumnVector& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nc != 1)
    (*current_liboctave_error_handler) ("column dimension mismatch for stack");

  octave_idx_type nr_insert = nr;
  ComplexMatrix retval (nr + a.numel (), nc);
  retval.insert (*this, 0, 0);
  retval.insert (a, nr_insert, 0);
  return retval;
}

ComplexMatrix
ComplexMatrix::stack (const ComplexDiagMatrix& a) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();
  if (nc != a.cols ())
    (*current_liboctave_error_handler) ("column dimension mismatch for stack");

  octave_idx_type nr_insert = nr;
  ComplexMatrix retval (nr + a.rows (), nc);
  retval.insert (*this, 0, 0);
  retval.insert (a, nr_insert, 0);
  return retval;
}

ComplexMatrix
conj (const ComplexMatrix& a)
{
  return do_mx_unary_map<Complex, Complex, std::conj<double>> (a);
}

// resize is the destructive equivalent for this one

ComplexMatrix
ComplexMatrix::extract (octave_idx_type r1, octave_idx_type c1,
                        octave_idx_type r2, octave_idx_type c2) const
{
  if (r1 > r2) { std::swap (r1, r2); }
  if (c1 > c2) { std::swap (c1, c2); }

  return index (octave::idx_vector (r1, r2+1), octave::idx_vector (c1, c2+1));
}

ComplexMatrix
ComplexMatrix::extract_n (octave_idx_type r1, octave_idx_type c1,
                          octave_idx_type nr, octave_idx_type nc) const
{
  return index (octave::idx_vector (r1, r1 + nr), octave::idx_vector (c1, c1 + nc));
}

// extract row or column i.

ComplexRowVector
ComplexMatrix::row (octave_idx_type i) const
{
  return index (octave::idx_vector (i), octave::idx_vector::colon);
}

ComplexColumnVector
ComplexMatrix::column (octave_idx_type i) const
{
  return index (octave::idx_vector::colon, octave::idx_vector (i));
}

// Local function to calculate the 1-norm.
static
double
norm1 (const ComplexMatrix& a)
{
  double anorm = 0.0;
  RowVector colsum = a.abs ().sum ().row (0);

  for (octave_idx_type i = 0; i < colsum.numel (); i++)
    {
      double sum = colsum.xelem (i);
      if (octave::math::isinf (sum) || octave::math::isnan (sum))
        {
          anorm = sum;  // Pass Inf or NaN to output
          break;
        }
      else
        anorm = std::max (anorm, sum);
    }

  return anorm;
}

ComplexMatrix
ComplexMatrix::inverse (void) const
{
  octave_idx_type info;
  double rcon;
  MatrixType mattype (*this);
  return inverse (mattype, info, rcon, 0, 0);
}

ComplexMatrix
ComplexMatrix::inverse (octave_idx_type& info) const
{
  double rcon;
  MatrixType mattype (*this);
  return inverse (mattype, info, rcon, 0, 0);
}

ComplexMatrix
ComplexMatrix::inverse (octave_idx_type& info, double& rcon, bool force,
                        bool calc_cond) const
{
  MatrixType mattype (*this);
  return inverse (mattype, info, rcon, force, calc_cond);
}

ComplexMatrix
ComplexMatrix::inverse (MatrixType& mattype) const
{
  octave_idx_type info;
  double rcon;
  return inverse (mattype, info, rcon, 0, 0);
}

ComplexMatrix
ComplexMatrix::inverse (MatrixType& mattype, octave_idx_type& info) const
{
  double rcon;
  return inverse (mattype, info, rcon, 0, 0);
}

ComplexMatrix
ComplexMatrix::tinverse (MatrixType& mattype, octave_idx_type& info,
                         double& rcon, bool force, bool calc_cond) const
{
  ComplexMatrix retval;

  F77_INT nr = octave::to_f77_int (rows ());
  F77_INT nc = octave::to_f77_int (cols ());

  if (nr != nc || nr == 0 || nc == 0)
    (*current_liboctave_error_handler) ("inverse requires square matrix");

  int typ = mattype.type ();
  char uplo = (typ == MatrixType::Lower ? 'L' : 'U');
  char udiag = 'N';
  retval = *this;
  Complex *tmp_data = retval.fortran_vec ();

  F77_INT tmp_info = 0;

  F77_XFCN (ztrtri, ZTRTRI, (F77_CONST_CHAR_ARG2 (&uplo, 1),
                             F77_CONST_CHAR_ARG2 (&udiag, 1),
                             nr, F77_DBLE_CMPLX_ARG (tmp_data), nr, tmp_info
                             F77_CHAR_ARG_LEN (1)
                             F77_CHAR_ARG_LEN (1)));

  info = tmp_info;

  // Throw away extra info LAPACK gives so as to not change output.
  rcon = 0.0;
  if (info != 0)
    info = -1;
  else if (calc_cond)
    {
      F77_INT ztrcon_info = 0;
      char job = '1';

      OCTAVE_LOCAL_BUFFER (Complex, cwork, 2*nr);
      OCTAVE_LOCAL_BUFFER (double, rwork, nr);

      F77_XFCN (ztrcon, ZTRCON, (F77_CONST_CHAR_ARG2 (&job, 1),
                                 F77_CONST_CHAR_ARG2 (&uplo, 1),
                                 F77_CONST_CHAR_ARG2 (&udiag, 1),
                                 nr, F77_DBLE_CMPLX_ARG (tmp_data), nr, rcon,
                                 F77_DBLE_CMPLX_ARG (cwork), rwork, ztrcon_info
                                 F77_CHAR_ARG_LEN (1)
                                 F77_CHAR_ARG_LEN (1)
                                 F77_CHAR_ARG_LEN (1)));

      if (ztrcon_info != 0)
        info = -1;
    }

  if (info == -1 && ! force)
    retval = *this; // Restore matrix contents.

  return retval;
}

ComplexMatrix
ComplexMatrix::finverse (MatrixType& mattype, octave_idx_type& info,
                         double& rcon, bool force, bool calc_cond) const
{
  ComplexMatrix retval;

  F77_INT nr = octave::to_f77_int (rows ());
  F77_INT nc = octave::to_f77_int (cols ());

  if (nr != nc)
    (*current_liboctave_error_handler) ("inverse requires square matrix");

  Array<F77_INT> ipvt (dim_vector (nr, 1));
  F77_INT *pipvt = ipvt.fortran_vec ();

  retval = *this;
  Complex *tmp_data = retval.fortran_vec ();

  Array<Complex> z (dim_vector (1, 1));
  F77_INT lwork = -1;

  // Query the optimum work array size.

  F77_INT tmp_info = 0;

  F77_XFCN (zgetri, ZGETRI, (nc, F77_DBLE_CMPLX_ARG (tmp_data), nr, pipvt,
                             F77_DBLE_CMPLX_ARG (z.fortran_vec ()), lwork,
                             tmp_info));

  lwork = static_cast<F77_INT> (std::real (z(0)));
  lwork = (lwork < 2 * nc ? 2 * nc : lwork);
  z.resize (dim_vector (lwork, 1));
  Complex *pz = z.fortran_vec ();

  info = 0;
  tmp_info = 0;

  // Calculate norm of the matrix (always, see bug #45577) for later use.
  double anorm = norm1 (retval);

  // Work around bug #45577, LAPACK crashes Octave if norm is NaN
  // and bug #46330, segfault with matrices containing Inf & NaN
  if (octave::math::isnan (anorm) || octave::math::isinf (anorm))
    info = -1;
  else
    {
      F77_XFCN (zgetrf, ZGETRF, (nc, nc, F77_DBLE_CMPLX_ARG (tmp_data), nr,
                                 pipvt, tmp_info));

      info = tmp_info;
    }

  // Throw away extra info LAPACK gives so as to not change output.
  rcon = 0.0;
  if (info != 0)
    info = -1;
  else if (calc_cond)
    {
      F77_INT zgecon_info = 0;

      // Now calculate the condition number for non-singular matrix.
      char job = '1';
      Array<double> rz (dim_vector (2 * nc, 1));
      double *prz = rz.fortran_vec ();
      F77_XFCN (zgecon, ZGECON, (F77_CONST_CHAR_ARG2 (&job, 1),
                                 nc, F77_DBLE_CMPLX_ARG (tmp_data), nr, anorm,
                                 rcon, F77_DBLE_CMPLX_ARG (pz), prz, zgecon_info
                                 F77_CHAR_ARG_LEN (1)));

      if (zgecon_info != 0)
        info = -1;
    }

  if ((info == -1 && ! force)
      || octave::math::isnan (anorm) || octave::math::isinf (anorm))
    retval = *this;  // Restore contents.
  else
    {
      F77_INT zgetri_info = 0;

      F77_XFCN (zgetri, ZGETRI, (nc, F77_DBLE_CMPLX_ARG (tmp_data), nr, pipvt,
                                 F77_DBLE_CMPLX_ARG (pz), lwork, zgetri_info));

      if (zgetri_info != 0)
        info = -1;
    }

  if (info != 0)
    mattype.mark_as_rectangular ();

  return retval;
}

ComplexMatrix
ComplexMatrix::inverse (MatrixType& mattype, octave_idx_type& info,
                        double& rcon, bool force, bool calc_cond) const
{
  int typ = mattype.type (false);
  ComplexMatrix ret;

  if (typ == MatrixType::Unknown)
    typ = mattype.type (*this);

  if (typ == MatrixType::Diagonal)  // a scalar is classified as Diagonal.
    {
      Complex scalar = this->elem (0);
      double real = std::real (scalar);
      double imag = std::imag (scalar);

      if (real == 0 && imag == 0)
        ret = ComplexMatrix (1, 1,
                             Complex (octave::numeric_limits<double>::Inf (), 0.0));
      else
        ret = Complex (1, 0) / (*this);

      if (calc_cond)
        {
          if (octave::math::isfinite (real) && octave::math::isfinite (imag)
              && (real != 0 || imag != 0))
            rcon = 1.0;
          else if (octave::math::isinf (real) || octave::math::isinf (imag)
                   || (real == 0 && imag == 0))
            rcon = 0.0;
          else
            rcon = octave::numeric_limits<double>::NaN ();
        }
    }
  else if (typ == MatrixType::Upper || typ == MatrixType::Lower)
    ret = tinverse (mattype, info, rcon, force, calc_cond);
  else
    {
      if (mattype.ishermitian ())
        {
          octave::math::chol<ComplexMatrix> chol (*this, info, true, calc_cond);
          if (info == 0)
            {
              if (calc_cond)
                rcon = chol.rcond ();
              else
                rcon = 1.0;
              ret = chol.inverse ();
            }
          else
            mattype.mark_as_unsymmetric ();
        }

      if (! mattype.ishermitian ())
        ret = finverse (mattype, info, rcon, force, calc_cond);

      if ((calc_cond || mattype.ishermitian ()) && rcon == 0.0)
        {
          ret = ComplexMatrix (rows (), columns (),
                               Complex (octave::numeric_limits<double>::Inf (), 0.0));
        }
    }

  return ret;
}

ComplexMatrix
ComplexMatrix::pseudo_inverse (double tol) const
{
  ComplexMatrix retval;

  octave::math::svd<ComplexMatrix> result (*this,
      octave::math::svd<ComplexMatrix>::Type::economy);

  DiagMatrix S = result.singular_values ();
  ComplexMatrix U = result.left_singular_matrix ();
  ComplexMatrix V = result.right_singular_matrix ();

  ColumnVector sigma = S.extract_diag ();

  octave_idx_type r = sigma.numel () - 1;
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (tol <= 0.0)
    {
      tol = std::max (nr, nc) * sigma.elem (0)
            * std::numeric_limits<double>::epsilon ();

      if (tol == 0)
        tol = std::numeric_limits<double>::min ();
    }

  while (r >= 0 && sigma.elem (r) < tol)
    r--;

  if (r < 0)
    retval = ComplexMatrix (nc, nr, 0.0);
  else
    {
      ComplexMatrix Ur = U.extract (0, 0, nr-1, r);
      DiagMatrix D = DiagMatrix (sigma.extract (0, r)).inverse ();
      ComplexMatrix Vr = V.extract (0, 0, nc-1, r);
      retval = Vr * D * Ur.hermitian ();
    }

  return retval;
}

#if defined (HAVE_FFTW)

ComplexMatrix
ComplexMatrix::fourier (void) const
{
  std::size_t nr = rows ();
  std::size_t nc = cols ();

  ComplexMatrix retval (nr, nc);

  std::size_t npts, nsamples;

  if (nr == 1 || nc == 1)
    {
      npts = (nr > nc ? nr : nc);
      nsamples = 1;
    }
  else
    {
      npts = nr;
      nsamples = nc;
    }

  const Complex *in (data ());
  Complex *out (retval.fortran_vec ());

  octave::fftw::fft (in, out, npts, nsamples);

  return retval;
}

ComplexMatrix
ComplexMatrix::ifourier (void) const
{
  std::size_t nr = rows ();
  std::size_t nc = cols ();

  ComplexMatrix retval (nr, nc);

  std::size_t npts, nsamples;

  if (nr == 1 || nc == 1)
    {
      npts = (nr > nc ? nr : nc);
      nsamples = 1;
    }
  else
    {
      npts = nr;
      nsamples = nc;
    }

  const Complex *in (data ());
  Complex *out (retval.fortran_vec ());

  octave::fftw::ifft (in, out, npts, nsamples);

  return retval;
}

ComplexMatrix
ComplexMatrix::fourier2d (void) const
{
  dim_vector dv (rows (), cols ());

  ComplexMatrix retval (rows (), cols ());
  const Complex *in (data ());
  Complex *out (retval.fortran_vec ());

  octave::fftw::fftNd (in, out, 2, dv);

  return retval;
}

ComplexMatrix
ComplexMatrix::ifourier2d (void) const
{
  dim_vector dv (rows (), cols ());

  ComplexMatrix retval (rows (), cols ());
  const Complex *in (data ());
  Complex *out (retval.fortran_vec ());

  octave::fftw::ifftNd (in, out, 2, dv);

  return retval;
}

#else

ComplexMatrix
ComplexMatrix::fourier (void) const
{
  (*current_liboctave_error_handler)
    ("support for FFTW was unavailable or disabled when liboctave was built");

  return ComplexMatrix ();
}

ComplexMatrix
ComplexMatrix::ifourier (void) const
{
  (*current_liboctave_error_handler)
    ("support for FFTW was unavailable or disabled when liboctave was built");

  return ComplexMatrix ();
}

ComplexMatrix
ComplexMatrix::fourier2d (void) const
{
  (*current_liboctave_error_handler)
    ("support for FFTW was unavailable or disabled when liboctave was built");

  return ComplexMatrix ();
}

ComplexMatrix
ComplexMatrix::ifourier2d (void) const
{
  (*current_liboctave_error_handler)
    ("support for FFTW was unavailable or disabled when liboctave was built");

  return ComplexMatrix ();
}

#endif

ComplexDET
ComplexMatrix::determinant (void) const
{
  octave_idx_type info;
  double rcon;
  return determinant (info, rcon, 0);
}

ComplexDET
ComplexMatrix::determinant (octave_idx_type& info) const
{
  double rcon;
  return determinant (info, rcon, 0);
}

ComplexDET
ComplexMatrix::determinant (octave_idx_type& info, double& rcon,
                            bool calc_cond) const
{
  MatrixType mattype (*this);
  return determinant (mattype, info, rcon, calc_cond);
}

ComplexDET
ComplexMatrix::determinant (MatrixType& mattype,
                            octave_idx_type& info, double& rcon,
                            bool calc_cond) const
{
  ComplexDET retval (1.0);

  info = 0;
  rcon = 0.0;

  F77_INT nr = octave::to_f77_int (rows ());
  F77_INT nc = octave::to_f77_int (cols ());

  if (nr != nc)
    (*current_liboctave_error_handler) ("matrix must be square");

  volatile int typ = mattype.type ();

  // Even though the matrix is marked as singular (Rectangular), we may
  // still get a useful number from the LU factorization, because it always
  // completes.

  if (typ == MatrixType::Unknown)
    typ = mattype.type (*this);
  else if (typ == MatrixType::Rectangular)
    typ = MatrixType::Full;

  if (typ == MatrixType::Lower || typ == MatrixType::Upper)
    {
      for (F77_INT i = 0; i < nc; i++)
        retval *= elem (i, i);
    }
  else if (typ == MatrixType::Hermitian)
    {
      ComplexMatrix atmp = *this;
      Complex *tmp_data = atmp.fortran_vec ();

      double anorm;
      if (calc_cond)
        anorm = norm1 (*this);

      F77_INT tmp_info = 0;

      char job = 'L';
      F77_XFCN (zpotrf, ZPOTRF, (F77_CONST_CHAR_ARG2 (&job, 1), nr,
                                 F77_DBLE_CMPLX_ARG (tmp_data), nr, tmp_info
                                 F77_CHAR_ARG_LEN (1)));

      info = tmp_info;

      if (info != 0)
        {
          rcon = 0.0;
          mattype.mark_as_unsymmetric ();
          typ = MatrixType::Full;
        }
      else
        {
          if (calc_cond)
            {
              Array<Complex> z (dim_vector (2 * nc, 1));
              Complex *pz = z.fortran_vec ();
              Array<double> rz (dim_vector (nc, 1));
              double *prz = rz.fortran_vec ();

              F77_XFCN (zpocon, ZPOCON, (F77_CONST_CHAR_ARG2 (&job, 1),
                                         nr, F77_DBLE_CMPLX_ARG (tmp_data), nr, anorm,
                                         rcon, F77_DBLE_CMPLX_ARG (pz), prz, tmp_info
                                         F77_CHAR_ARG_LEN (1)));

              info = tmp_info;

              if (info != 0)
                rcon = 0.0;
            }

          for (F77_INT i = 0; i < nc; i++)
            retval *= atmp(i, i);

          retval = retval.square ();
        }
    }
  else if (typ != MatrixType::Full)
    (*current_liboctave_error_handler) ("det: invalid dense matrix type");

  if (typ == MatrixType::Full)
    {
      Array<F77_INT> ipvt (dim_vector (nr, 1));
      F77_INT *pipvt = ipvt.fortran_vec ();

      ComplexMatrix atmp = *this;
      Complex *tmp_data = atmp.fortran_vec ();

      info = 0;

      // Calculate norm of the matrix (always, see bug #45577) for later use.
      double anorm = norm1 (*this);

      F77_INT tmp_info = 0;

      // Work around bug #45577, LAPACK crashes Octave if norm is NaN
      if (octave::math::isnan (anorm))
        info = -1;
      else
        {
          F77_XFCN (zgetrf, ZGETRF, (nr, nr, F77_DBLE_CMPLX_ARG (tmp_data), nr, pipvt,
                                     tmp_info));

          info = tmp_info;
        }

      // Throw away extra info LAPACK gives so as to not change output.
      rcon = 0.0;
      if (info != 0)
        {
          info = -1;
          retval = ComplexDET ();
        }
      else
        {
          if (calc_cond)
            {
              // Now calc the condition number for non-singular matrix.
              char job = '1';
              Array<Complex> z (dim_vector (2 * nc, 1));
              Complex *pz = z.fortran_vec ();
              Array<double> rz (dim_vector (2 * nc, 1));
              double *prz = rz.fortran_vec ();

              F77_XFCN (zgecon, ZGECON, (F77_CONST_CHAR_ARG2 (&job, 1),
                                         nc, F77_DBLE_CMPLX_ARG (tmp_data), nr, anorm,
                                         rcon, F77_DBLE_CMPLX_ARG (pz), prz, tmp_info
                                         F77_CHAR_ARG_LEN (1)));

              info = tmp_info;
            }

          if (info != 0)
            {
              info = -1;
              retval = ComplexDET ();
            }
          else
            {
              for (F77_INT i = 0; i < nc; i++)
                {
                  Complex c = atmp(i, i);
                  retval *= (ipvt(i) != (i+1)) ? -c : c;
                }
            }
        }
    }

  return retval;
}

double
ComplexMatrix::rcond (void) const
{
  MatrixType mattype (*this);
  return rcond (mattype);
}

double
ComplexMatrix::rcond (MatrixType& mattype) const
{
  double rcon = octave::numeric_limits<double>::NaN ();
  F77_INT nr = octave::to_f77_int (rows ());
  F77_INT nc = octave::to_f77_int (cols ());

  if (nr != nc)
    (*current_liboctave_error_handler) ("matrix must be square");

  if (nr == 0 || nc == 0)
    rcon = octave::numeric_limits<double>::Inf ();
  else
    {
      volatile int typ = mattype.type ();

      if (typ == MatrixType::Unknown)
        typ = mattype.type (*this);

      // Only calculate the condition number for LU/Cholesky
      if (typ == MatrixType::Upper)
        {
          const Complex *tmp_data = data ();
          F77_INT info = 0;
          char norm = '1';
          char uplo = 'U';
          char dia = 'N';

          Array<Complex> z (dim_vector (2 * nc, 1));
          Complex *pz = z.fortran_vec ();
          Array<double> rz (dim_vector (nc, 1));
          double *prz = rz.fortran_vec ();

          F77_XFCN (ztrcon, ZTRCON, (F77_CONST_CHAR_ARG2 (&norm, 1),
                                     F77_CONST_CHAR_ARG2 (&uplo, 1),
                                     F77_CONST_CHAR_ARG2 (&dia, 1),
                                     nr, F77_CONST_DBLE_CMPLX_ARG (tmp_data), nr, rcon,
                                     F77_DBLE_CMPLX_ARG (pz), prz, info
                                     F77_CHAR_ARG_LEN (1)
                                     F77_CHAR_ARG_LEN (1)
                                     F77_CHAR_ARG_LEN (1)));

          if (info != 0)
            rcon = 0;
        }
      else if (typ == MatrixType::Permuted_Upper)
        (*current_liboctave_error_handler)
          ("permuted triangular matrix not implemented");
      else if (typ == MatrixType::Lower)
        {
          const Complex *tmp_data = data ();
          F77_INT info = 0;
          char norm = '1';
          char uplo = 'L';
          char dia = 'N';

          Array<Complex> z (dim_vector (2 * nc, 1));
          Complex *pz = z.fortran_vec ();
          Array<double> rz (dim_vector (nc, 1));
          double *prz = rz.fortran_vec ();

          F77_XFCN (ztrcon, ZTRCON, (F77_CONST_CHAR_ARG2 (&norm, 1),
                                     F77_CONST_CHAR_ARG2 (&uplo, 1),
                                     F77_CONST_CHAR_ARG2 (&dia, 1),
                                     nr, F77_CONST_DBLE_CMPLX_ARG (tmp_data), nr, rcon,
                                     F77_DBLE_CMPLX_ARG (pz), prz, info
                                     F77_CHAR_ARG_LEN (1)
                                     F77_CHAR_ARG_LEN (1)
                                     F77_CHAR_ARG_LEN (1)));

          if (info != 0)
            rcon = 0.0;
        }
      else if (typ == MatrixType::Permuted_Lower)
        (*current_liboctave_error_handler)
          ("permuted triangular matrix not implemented");
      else if (typ == MatrixType::Full || typ == MatrixType::Hermitian)
        {
          double anorm = -1.0;

          if (typ == MatrixType::Hermitian)
            {
              F77_INT info = 0;
              char job = 'L';

              ComplexMatrix atmp = *this;
              Complex *tmp_data = atmp.fortran_vec ();

              anorm = norm1 (atmp);

              F77_XFCN (zpotrf, ZPOTRF, (F77_CONST_CHAR_ARG2 (&job, 1), nr,
                                         F77_DBLE_CMPLX_ARG (tmp_data), nr, info
                                         F77_CHAR_ARG_LEN (1)));

              if (info != 0)
                {
                  rcon = 0.0;

                  mattype.mark_as_unsymmetric ();
                  typ = MatrixType::Full;
                }
              else
                {
                  Array<Complex> z (dim_vector (2 * nc, 1));
                  Complex *pz = z.fortran_vec ();
                  Array<double> rz (dim_vector (nc, 1));
                  double *prz = rz.fortran_vec ();

                  F77_XFCN (zpocon, ZPOCON, (F77_CONST_CHAR_ARG2 (&job, 1),
                                             nr, F77_DBLE_CMPLX_ARG (tmp_data), nr, anorm,
                                             rcon, F77_DBLE_CMPLX_ARG (pz), prz, info
                                             F77_CHAR_ARG_LEN (1)));

                  if (info != 0)
                    rcon = 0.0;
                }
            }

          if (typ == MatrixType::Full)
            {
              F77_INT info = 0;

              ComplexMatrix atmp = *this;
              Complex *tmp_data = atmp.fortran_vec ();

              Array<F77_INT> ipvt (dim_vector (nr, 1));
              F77_INT *pipvt = ipvt.fortran_vec ();

              if (anorm < 0.0)
                anorm = norm1 (atmp);

              Array<Complex> z (dim_vector (2 * nc, 1));
              Complex *pz = z.fortran_vec ();
              Array<double> rz (dim_vector (2 * nc, 1));
              double *prz = rz.fortran_vec ();

              // Work around bug #45577, LAPACK crashes Octave if norm is NaN
              if (octave::math::isnan (anorm))
                info = -1;
              else
                F77_XFCN (zgetrf, ZGETRF, (nr, nr,
                                           F77_DBLE_CMPLX_ARG (tmp_data),
                                           nr, pipvt, info));

              if (info != 0)
                {
                  rcon = 0.0;
                  mattype.mark_as_rectangular ();
                }
              else
                {
                  char job = '1';
                  F77_XFCN (zgecon, ZGECON, (F77_CONST_CHAR_ARG2 (&job, 1),
                                             nc, F77_DBLE_CMPLX_ARG (tmp_data), nr, anorm,
                                             rcon, F77_DBLE_CMPLX_ARG (pz), prz, info
                                             F77_CHAR_ARG_LEN (1)));

                  if (info != 0)
                    rcon = 0.0;
                }
            }
        }
      else
        rcon = 0.0;
    }

  return rcon;
}

ComplexMatrix
ComplexMatrix::utsolve (MatrixType& mattype, const ComplexMatrix& b,
                        octave_idx_type& info, double& rcon,
                        solve_singularity_handler sing_handler,
                        bool calc_cond, blas_trans_type transt) const
{
  ComplexMatrix retval;

  F77_INT nr = octave::to_f77_int (rows ());
  F77_INT nc = octave::to_f77_int (cols ());

  F77_INT b_nr = octave::to_f77_int (b.rows ());
  F77_INT b_nc = octave::to_f77_int (b.cols ());

  if (nr != b_nr)
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");

  if (nr == 0 || nc == 0 || b_nc == 0)
    retval = ComplexMatrix (nc, b_nc, Complex (0.0, 0.0));
  else
    {
      volatile int typ = mattype.type ();

      if (typ != MatrixType::Permuted_Upper && typ != MatrixType::Upper)
        (*current_liboctave_error_handler) ("incorrect matrix type");

      rcon = 1.0;
      info = 0;

      if (typ == MatrixType::Permuted_Upper)
        (*current_liboctave_error_handler)
          ("permuted triangular matrix not implemented");

      const Complex *tmp_data = data ();

      retval = b;
      Complex *result = retval.fortran_vec ();

      char uplo = 'U';
      char trans = get_blas_char (transt);
      char dia = 'N';

      F77_INT tmp_info = 0;

      F77_XFCN (ztrtrs, ZTRTRS, (F77_CONST_CHAR_ARG2 (&uplo, 1),
                                 F77_CONST_CHAR_ARG2 (&trans, 1),
                                 F77_CONST_CHAR_ARG2 (&dia, 1),
                                 nr, b_nc, F77_CONST_DBLE_CMPLX_ARG (tmp_data), nr,
                                 F77_DBLE_CMPLX_ARG (result), nr, tmp_info
                                 F77_CHAR_ARG_LEN (1)
                                 F77_CHAR_ARG_LEN (1)
                                 F77_CHAR_ARG_LEN (1)));

      info = tmp_info;

      if (calc_cond)
        {
          char norm = '1';
          uplo = 'U';
          dia = 'N';

          Array<Complex> z (dim_vector (2 * nc, 1));
          Complex *pz = z.fortran_vec ();
          Array<double> rz (dim_vector (nc, 1));
          double *prz = rz.fortran_vec ();

          F77_XFCN (ztrcon, ZTRCON, (F77_CONST_CHAR_ARG2 (&norm, 1),
                                     F77_CONST_CHAR_ARG2 (&uplo, 1),
                                     F77_CONST_CHAR_ARG2 (&dia, 1),
                                     nr, F77_CONST_DBLE_CMPLX_ARG (tmp_data), nr, rcon,
                                     F77_DBLE_CMPLX_ARG (pz), prz, tmp_info
                                     F77_CHAR_ARG_LEN (1)
                                     F77_CHAR_ARG_LEN (1)
                                     F77_CHAR_ARG_LEN (1)));

          info = tmp_info;

          if (info != 0)
            info = -2;

          volatile double rcond_plus_one = rcon + 1.0;

          if (rcond_plus_one == 1.0 || octave::math::isnan (rcon))
            {
              info = -2;

              if (sing_handler)
                sing_handler (rcon);
              else
                octave::warn_singular_matrix (rcon);
            }
        }
    }

  return retval;
}

ComplexMatrix
ComplexMatrix::ltsolve (MatrixType& mattype, const ComplexMatrix& b,
                        octave_idx_type& info, double& rcon,
                        solve_singularity_handler sing_handler,
                        bool calc_cond, blas_trans_type transt) const
{
  ComplexMatrix retval;

  F77_INT nr = octave::to_f77_int (rows ());
  F77_INT nc = octave::to_f77_int (cols ());

  F77_INT b_nr = octave::to_f77_int (b.rows ());
  F77_INT b_nc = octave::to_f77_int (b.cols ());

  if (nr != b_nr)
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");

  if (nr == 0 || nc == 0 || b_nc == 0)
    retval = ComplexMatrix (nc, b_nc, Complex (0.0, 0.0));
  else
    {
      volatile int typ = mattype.type ();

      if (typ != MatrixType::Permuted_Lower && typ != MatrixType::Lower)
        (*current_liboctave_error_handler) ("incorrect matrix type");

      rcon = 1.0;
      info = 0;

      if (typ == MatrixType::Permuted_Lower)
        (*current_liboctave_error_handler)
          ("permuted triangular matrix not implemented");

      const Complex *tmp_data = data ();

      retval = b;
      Complex *result = retval.fortran_vec ();

      char uplo = 'L';
      char trans = get_blas_char (transt);
      char dia = 'N';

      F77_INT tmp_info = 0;

      F77_XFCN (ztrtrs, ZTRTRS, (F77_CONST_CHAR_ARG2 (&uplo, 1),
                                 F77_CONST_CHAR_ARG2 (&trans, 1),
                                 F77_CONST_CHAR_ARG2 (&dia, 1),
                                 nr, b_nc, F77_CONST_DBLE_CMPLX_ARG (tmp_data), nr,
                                 F77_DBLE_CMPLX_ARG (result), nr, tmp_info
                                 F77_CHAR_ARG_LEN (1)
                                 F77_CHAR_ARG_LEN (1)
                                 F77_CHAR_ARG_LEN (1)));

      info = tmp_info;

      if (calc_cond)
        {
          char norm = '1';
          uplo = 'L';
          dia = 'N';

          Array<Complex> z (dim_vector (2 * nc, 1));
          Complex *pz = z.fortran_vec ();
          Array<double> rz (dim_vector (nc, 1));
          double *prz = rz.fortran_vec ();

          F77_XFCN (ztrcon, ZTRCON, (F77_CONST_CHAR_ARG2 (&norm, 1),
                                     F77_CONST_CHAR_ARG2 (&uplo, 1),
                                     F77_CONST_CHAR_ARG2 (&dia, 1),
                                     nr, F77_CONST_DBLE_CMPLX_ARG (tmp_data), nr, rcon,
                                     F77_DBLE_CMPLX_ARG (pz), prz, tmp_info
                                     F77_CHAR_ARG_LEN (1)
                                     F77_CHAR_ARG_LEN (1)
                                     F77_CHAR_ARG_LEN (1)));

          info = tmp_info;

          if (info != 0)
            info = -2;

          volatile double rcond_plus_one = rcon + 1.0;

          if (rcond_plus_one == 1.0 || octave::math::isnan (rcon))
            {
              info = -2;

              if (sing_handler)
                sing_handler (rcon);
              else
                octave::warn_singular_matrix (rcon);
            }
        }
    }

  return retval;
}

ComplexMatrix
ComplexMatrix::fsolve (MatrixType& mattype, const ComplexMatrix& b,
                       octave_idx_type& info, double& rcon,
                       solve_singularity_handler sing_handler,
                       bool calc_cond) const
{
  ComplexMatrix retval;

  F77_INT nr = octave::to_f77_int (rows ());
  F77_INT nc = octave::to_f77_int (cols ());

  F77_INT b_nr = octave::to_f77_int (b.rows ());
  F77_INT b_nc = octave::to_f77_int (b.cols ());

  if (nr != nc || nr != b_nr)
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");

  if (nr == 0 || b_nc == 0)
    retval = ComplexMatrix (nc, b_nc, Complex (0.0, 0.0));
  else
    {
      volatile int typ = mattype.type ();

      // Calculate the norm of the matrix for later use when determining rcon.
      double anorm = -1.0;

      if (typ == MatrixType::Hermitian)
        {
          info = 0;
          char job = 'L';

          ComplexMatrix atmp = *this;
          Complex *tmp_data = atmp.fortran_vec ();

          // The norm of the matrix for later use when determining rcon.
          if (calc_cond)
            anorm = norm1 (atmp);

          F77_INT tmp_info = 0;

          F77_XFCN (zpotrf, ZPOTRF, (F77_CONST_CHAR_ARG2 (&job, 1), nr,
                                     F77_DBLE_CMPLX_ARG (tmp_data), nr, tmp_info
                                     F77_CHAR_ARG_LEN (1)));

          info = tmp_info;

          // Throw away extra info LAPACK gives so as to not change output.
          rcon = 0.0;
          if (info != 0)
            {
              info = -2;

              mattype.mark_as_unsymmetric ();
              typ = MatrixType::Full;
            }
          else
            {
              if (calc_cond)
                {
                  Array<Complex> z (dim_vector (2 * nc, 1));
                  Complex *pz = z.fortran_vec ();
                  Array<double> rz (dim_vector (nc, 1));
                  double *prz = rz.fortran_vec ();

                  F77_XFCN (zpocon, ZPOCON, (F77_CONST_CHAR_ARG2 (&job, 1),
                                             nr, F77_DBLE_CMPLX_ARG (tmp_data), nr, anorm,
                                             rcon, F77_DBLE_CMPLX_ARG (pz), prz, tmp_info
                                             F77_CHAR_ARG_LEN (1)));

                  info = tmp_info;

                  if (info != 0)
                    info = -2;

                  volatile double rcond_plus_one = rcon + 1.0;

                  if (rcond_plus_one == 1.0 || octave::math::isnan (rcon))
                    {
                      info = -2;

                      if (sing_handler)
                        sing_handler (rcon);
                      else
                        octave::warn_singular_matrix (rcon);
                    }
                }

              if (info == 0)
                {
                  retval = b;
                  Complex *result = retval.fortran_vec ();

                  F77_XFCN (zpotrs, ZPOTRS, (F77_CONST_CHAR_ARG2 (&job, 1),
                                             nr, b_nc, F77_DBLE_CMPLX_ARG (tmp_data), nr,
                                             F77_DBLE_CMPLX_ARG (result), b_nr, tmp_info
                                             F77_CHAR_ARG_LEN (1)));

                  info = tmp_info;
                }
              else
                {
                  mattype.mark_as_unsymmetric ();
                  typ = MatrixType::Full;
                }
            }
        }

      if (typ == MatrixType::Full)
        {
          info = 0;

          Array<F77_INT> ipvt (dim_vector (nr, 1));
          F77_INT *pipvt = ipvt.fortran_vec ();

          ComplexMatrix atmp = *this;
          Complex *tmp_data = atmp.fortran_vec ();

          Array<Complex> z (dim_vector (2 * nc, 1));
          Complex *pz = z.fortran_vec ();
          Array<double> rz (dim_vector (2 * nc, 1));
          double *prz = rz.fortran_vec ();

          // Calculate the norm of the matrix, for later use.
          if (calc_cond && anorm < 0.0)
            anorm = norm1 (atmp);

          F77_INT tmp_info = 0;

          // Work around bug #45577, LAPACK crashes Octave if norm is NaN
          // and bug #46330, segfault with matrices containing Inf & NaN
          if (octave::math::isnan (anorm) || octave::math::isinf (anorm))
            info = -2;
          else
            {
              F77_XFCN (zgetrf, ZGETRF, (nr, nr, F77_DBLE_CMPLX_ARG (tmp_data),
                                         nr, pipvt, tmp_info));

              info = tmp_info;
            }

          // Throw away extra info LAPACK gives so as to not change output.
          rcon = 0.0;
          if (info != 0)
            {
              info = -2;

              if (sing_handler)
                sing_handler (rcon);
              else
                octave::warn_singular_matrix ();

              mattype.mark_as_rectangular ();
            }
          else
            {
              if (calc_cond)
                {
                  // Calculate the condition number for non-singular matrix.
                  char job = '1';
                  F77_XFCN (zgecon, ZGECON, (F77_CONST_CHAR_ARG2 (&job, 1),
                                             nc, F77_DBLE_CMPLX_ARG (tmp_data), nr, anorm,
                                             rcon, F77_DBLE_CMPLX_ARG (pz), prz, tmp_info
                                             F77_CHAR_ARG_LEN (1)));

                  info = tmp_info;

                  if (info != 0)
                    info = -2;

                  volatile double rcond_plus_one = rcon + 1.0;

                  if (rcond_plus_one == 1.0 || octave::math::isnan (rcon))
                    {
                      if (sing_handler)
                        sing_handler (rcon);
                      else
                        octave::warn_singular_matrix (rcon);
                    }
                }

              if (info == 0)
                {
                  retval = b;
                  Complex *result = retval.fortran_vec ();

                  char job = 'N';
                  F77_XFCN (zgetrs, ZGETRS, (F77_CONST_CHAR_ARG2 (&job, 1),
                                             nr, b_nc, F77_DBLE_CMPLX_ARG (tmp_data), nr,
                                             pipvt, F77_DBLE_CMPLX_ARG (result), b_nr, tmp_info
                                             F77_CHAR_ARG_LEN (1)));

                  info = tmp_info;
                }
              else
                mattype.mark_as_rectangular ();
            }
        }

      if (octave::math::isinf (anorm))
        {
          retval = ComplexMatrix (b_nr, b_nc, Complex (0, 0));
          mattype.mark_as_full ();
        }
    }

  return retval;
}

ComplexMatrix
ComplexMatrix::solve (MatrixType& mattype, const Matrix& b) const
{
  octave_idx_type info;
  double rcon;
  return solve (mattype, b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (MatrixType& mattype, const Matrix& b,
                      octave_idx_type& info) const
{
  double rcon;
  return solve (mattype, b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (MatrixType& mattype, const Matrix& b,
                      octave_idx_type& info, double& rcon) const
{
  return solve (mattype, b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (MatrixType& mattype, const Matrix& b,
                      octave_idx_type& info, double& rcon,
                      solve_singularity_handler sing_handler,
                      bool singular_fallback, blas_trans_type transt) const
{
  ComplexMatrix tmp (b);
  return solve (mattype, tmp, info, rcon, sing_handler, singular_fallback,
                transt);
}

ComplexMatrix
ComplexMatrix::solve (MatrixType& mattype, const ComplexMatrix& b) const
{
  octave_idx_type info;
  double rcon;
  return solve (mattype, b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (MatrixType& mattype, const ComplexMatrix& b,
                      octave_idx_type& info) const
{
  double rcon;
  return solve (mattype, b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (MatrixType& mattype, const ComplexMatrix& b,
                      octave_idx_type& info, double& rcon) const
{
  return solve (mattype, b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (MatrixType& mattype, const ComplexMatrix& b,
                      octave_idx_type& info, double& rcon,
                      solve_singularity_handler sing_handler,
                      bool singular_fallback, blas_trans_type transt) const
{
  ComplexMatrix retval;
  int typ = mattype.type ();

  if (typ == MatrixType::Unknown)
    typ = mattype.type (*this);

  // Only calculate the condition number for LU/Cholesky
  if (typ == MatrixType::Upper || typ == MatrixType::Permuted_Upper)
    retval = utsolve (mattype, b, info, rcon, sing_handler, true, transt);
  else if (typ == MatrixType::Lower || typ == MatrixType::Permuted_Lower)
    retval = ltsolve (mattype, b, info, rcon, sing_handler, true, transt);
  else if (transt == blas_trans)
    return transpose ().solve (mattype, b, info, rcon, sing_handler,
                               singular_fallback);
  else if (transt == blas_conj_trans)
    retval = hermitian ().solve (mattype, b, info, rcon, sing_handler,
                                 singular_fallback);
  else if (typ == MatrixType::Full || typ == MatrixType::Hermitian)
    retval = fsolve (mattype, b, info, rcon, sing_handler, true);
  else if (typ != MatrixType::Rectangular)
    (*current_liboctave_error_handler) ("unknown matrix type");

  // Rectangular or one of the above solvers flags a singular matrix
  if (singular_fallback && mattype.type () == MatrixType::Rectangular)
    {
      octave_idx_type rank;
      retval = lssolve (b, info, rank, rcon);
    }

  return retval;
}

ComplexColumnVector
ComplexMatrix::solve (MatrixType& mattype, const ColumnVector& b) const
{
  octave_idx_type info;
  double rcon;
  return solve (mattype, ComplexColumnVector (b), info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (MatrixType& mattype, const ColumnVector& b,
                      octave_idx_type& info) const
{
  double rcon;
  return solve (mattype, ComplexColumnVector (b), info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (MatrixType& mattype, const ColumnVector& b,
                      octave_idx_type& info, double& rcon) const
{
  return solve (mattype, ComplexColumnVector (b), info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (MatrixType& mattype, const ColumnVector& b,
                      octave_idx_type& info, double& rcon,
                      solve_singularity_handler sing_handler,
                      blas_trans_type transt) const
{
  return solve (mattype, ComplexColumnVector (b), info, rcon, sing_handler,
                transt);
}

ComplexColumnVector
ComplexMatrix::solve (MatrixType& mattype, const ComplexColumnVector& b) const
{
  octave_idx_type info;
  double rcon;
  return solve (mattype, b, info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (MatrixType& mattype, const ComplexColumnVector& b,
                      octave_idx_type& info) const
{
  double rcon;
  return solve (mattype, b, info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (MatrixType& mattype, const ComplexColumnVector& b,
                      octave_idx_type& info, double& rcon) const
{
  return solve (mattype, b, info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (MatrixType& mattype, const ComplexColumnVector& b,
                      octave_idx_type& info, double& rcon,
                      solve_singularity_handler sing_handler,
                      blas_trans_type transt) const
{

  ComplexMatrix tmp (b);
  tmp = solve (mattype, tmp, info, rcon, sing_handler, true, transt);
  return tmp.column (static_cast<octave_idx_type> (0));
}

ComplexMatrix
ComplexMatrix::solve (const Matrix& b) const
{
  octave_idx_type info;
  double rcon;
  return solve (b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (const Matrix& b, octave_idx_type& info) const
{
  double rcon;
  return solve (b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (const Matrix& b, octave_idx_type& info,
                      double& rcon) const
{
  return solve (b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (const Matrix& b, octave_idx_type& info, double& rcon,
                      solve_singularity_handler sing_handler,
                      blas_trans_type transt) const
{
  ComplexMatrix tmp (b);
  return solve (tmp, info, rcon, sing_handler, transt);
}

ComplexMatrix
ComplexMatrix::solve (const ComplexMatrix& b) const
{
  octave_idx_type info;
  double rcon;
  return solve (b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (const ComplexMatrix& b, octave_idx_type& info) const
{
  double rcon;
  return solve (b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (const ComplexMatrix& b, octave_idx_type& info,
                      double& rcon) const
{
  return solve (b, info, rcon, nullptr);
}

ComplexMatrix
ComplexMatrix::solve (const ComplexMatrix& b, octave_idx_type& info,
                      double& rcon,
                      solve_singularity_handler sing_handler,
                      blas_trans_type transt) const
{
  MatrixType mattype (*this);
  return solve (mattype, b, info, rcon, sing_handler, true, transt);
}

ComplexColumnVector
ComplexMatrix::solve (const ColumnVector& b) const
{
  octave_idx_type info;
  double rcon;
  return solve (ComplexColumnVector (b), info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (const ColumnVector& b, octave_idx_type& info) const
{
  double rcon;
  return solve (ComplexColumnVector (b), info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (const ColumnVector& b, octave_idx_type& info,
                      double& rcon) const
{
  return solve (ComplexColumnVector (b), info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (const ColumnVector& b, octave_idx_type& info,
                      double& rcon,
                      solve_singularity_handler sing_handler,
                      blas_trans_type transt) const
{
  return solve (ComplexColumnVector (b), info, rcon, sing_handler, transt);
}

ComplexColumnVector
ComplexMatrix::solve (const ComplexColumnVector& b) const
{
  octave_idx_type info;
  double rcon;
  return solve (b, info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (const ComplexColumnVector& b, octave_idx_type& info) const
{
  double rcon;
  return solve (b, info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (const ComplexColumnVector& b, octave_idx_type& info,
                      double& rcon) const
{
  return solve (b, info, rcon, nullptr);
}

ComplexColumnVector
ComplexMatrix::solve (const ComplexColumnVector& b, octave_idx_type& info,
                      double& rcon,
                      solve_singularity_handler sing_handler,
                      blas_trans_type transt) const
{
  MatrixType mattype (*this);
  return solve (mattype, b, info, rcon, sing_handler, transt);
}

ComplexMatrix
ComplexMatrix::lssolve (const Matrix& b) const
{
  octave_idx_type info;
  octave_idx_type rank;
  double rcon;
  return lssolve (ComplexMatrix (b), info, rank, rcon);
}

ComplexMatrix
ComplexMatrix::lssolve (const Matrix& b, octave_idx_type& info) const
{
  octave_idx_type rank;
  double rcon;
  return lssolve (ComplexMatrix (b), info, rank, rcon);
}

ComplexMatrix
ComplexMatrix::lssolve (const Matrix& b, octave_idx_type& info,
                        octave_idx_type& rank) const
{
  double rcon;
  return lssolve (ComplexMatrix (b), info, rank, rcon);
}

ComplexMatrix
ComplexMatrix::lssolve (const Matrix& b, octave_idx_type& info,
                        octave_idx_type& rank, double& rcon) const
{
  return lssolve (ComplexMatrix (b), info, rank, rcon);
}

ComplexMatrix
ComplexMatrix::lssolve (const ComplexMatrix& b) const
{
  octave_idx_type info;
  octave_idx_type rank;
  double rcon;
  return lssolve (b, info, rank, rcon);
}

ComplexMatrix
ComplexMatrix::lssolve (const ComplexMatrix& b, octave_idx_type& info) const
{
  octave_idx_type rank;
  double rcon;
  return lssolve (b, info, rank, rcon);
}

ComplexMatrix
ComplexMatrix::lssolve (const ComplexMatrix& b, octave_idx_type& info,
                        octave_idx_type& rank) const
{
  double rcon;
  return lssolve (b, info, rank, rcon);
}

ComplexMatrix
ComplexMatrix::lssolve (const ComplexMatrix& b, octave_idx_type& info,
                        octave_idx_type& rank, double& rcon) const
{
  ComplexMatrix retval;

  F77_INT m = octave::to_f77_int (rows ());
  F77_INT n = octave::to_f77_int (cols ());

  F77_INT b_nr = octave::to_f77_int (b.rows ());
  F77_INT b_nc = octave::to_f77_int (b.cols ());
  F77_INT nrhs = b_nc;  // alias for code readability

  if (m != b_nr)
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");

  if (m == 0 || n == 0 || b_nc == 0)
    retval = ComplexMatrix (n, b_nc, Complex (0.0, 0.0));
  else
    {
      volatile F77_INT minmn = (m < n ? m : n);
      F77_INT maxmn = (m > n ? m : n);
      rcon = -1.0;

      if (m != n)
        {
          retval = ComplexMatrix (maxmn, nrhs);

          for (F77_INT j = 0; j < nrhs; j++)
            for (F77_INT i = 0; i < m; i++)
              retval.elem (i, j) = b.elem (i, j);
        }
      else
        retval = b;

      ComplexMatrix atmp = *this;
      Complex *tmp_data = atmp.fortran_vec ();

      Complex *pretval = retval.fortran_vec ();
      Array<double> s (dim_vector (minmn, 1));
      double *ps = s.fortran_vec ();

      // Ask ZGELSD what the dimension of WORK should be.
      F77_INT lwork = -1;

      Array<Complex> work (dim_vector (1, 1));

      F77_INT smlsiz;
      F77_FUNC (xilaenv, XILAENV) (9, F77_CONST_CHAR_ARG2 ("ZGELSD", 6),
                                   F77_CONST_CHAR_ARG2 (" ", 1),
                                   0, 0, 0, 0, smlsiz
                                   F77_CHAR_ARG_LEN (6)
                                   F77_CHAR_ARG_LEN (1));

      F77_INT mnthr;
      F77_FUNC (xilaenv, XILAENV) (6, F77_CONST_CHAR_ARG2 ("ZGELSD", 6),
                                   F77_CONST_CHAR_ARG2 (" ", 1),
                                   m, n, nrhs, -1, mnthr
                                   F77_CHAR_ARG_LEN (6)
                                   F77_CHAR_ARG_LEN (1));

      // We compute the size of rwork and iwork because ZGELSD in
      // older versions of LAPACK does not return them on a query
      // call.
      double dminmn = static_cast<double> (minmn);
      double dsmlsizp1 = static_cast<double> (smlsiz+1);
      double tmp = octave::math::log2 (dminmn / dsmlsizp1);

      F77_INT nlvl = static_cast<F77_INT> (tmp) + 1;
      if (nlvl < 0)
        nlvl = 0;

      F77_INT lrwork = minmn*(10 + 2*smlsiz + 8*nlvl)
                       + 3*smlsiz*nrhs
                       + std::max ((smlsiz+1)*(smlsiz+1),
                                   n*(1+nrhs) + 2*nrhs);
      if (lrwork < 1)
        lrwork = 1;
      Array<double> rwork (dim_vector (lrwork, 1));
      double *prwork = rwork.fortran_vec ();

      F77_INT liwork = 3 * minmn * nlvl + 11 * minmn;
      if (liwork < 1)
        liwork = 1;
      Array<F77_INT> iwork (dim_vector (liwork, 1));
      F77_INT *piwork = iwork.fortran_vec ();

      F77_INT tmp_info = 0;
      F77_INT tmp_rank = 0;

      F77_XFCN (zgelsd, ZGELSD, (m, n, nrhs, F77_DBLE_CMPLX_ARG (tmp_data), m,
                                 F77_DBLE_CMPLX_ARG (pretval), maxmn,
                                 ps, rcon, tmp_rank, F77_DBLE_CMPLX_ARG (work.fortran_vec ()),
                                 lwork, prwork, piwork, tmp_info));

      info = tmp_info;
      rank = tmp_rank;

      // The workspace query is broken in at least LAPACK 3.0.0
      // through 3.1.1 when n >= mnthr.  The obtuse formula below
      // should provide sufficient workspace for ZGELSD to operate
      // efficiently.
      if (n > m && n >= mnthr)
        {
          F77_INT addend = m;

          if (2*m-4 > addend)
            addend = 2*m-4;

          if (nrhs > addend)
            addend = nrhs;

          if (n-3*m > addend)
            addend = n-3*m;

          const F77_INT lworkaround = 4*m + m*m + addend;

          if (std::real (work(0)) < lworkaround)
            work(0) = lworkaround;
        }
      else if (m >= n)
        {
          F77_INT lworkaround = 2*m + m*nrhs;

          if (std::real (work(0)) < lworkaround)
            work(0) = lworkaround;
        }

      lwork = static_cast<F77_INT> (std::real (work(0)));
      work.resize (dim_vector (lwork, 1));

      double anorm = norm1 (*this);

      if (octave::math::isinf (anorm))
        {
          rcon = 0.0;
          retval = ComplexMatrix (n, b_nc, 0.0);
        }
      else if (octave::math::isnan (anorm))
        {
          rcon = octave::numeric_limits<double>::NaN ();
          retval = ComplexMatrix (n, b_nc,
                                  octave::numeric_limits<double>::NaN ());
        }
      else
        {
          F77_XFCN (zgelsd, ZGELSD, (m, n, nrhs, F77_DBLE_CMPLX_ARG (tmp_data),
                                     m, F77_DBLE_CMPLX_ARG (pretval),
                                     maxmn, ps, rcon, tmp_rank,
                                     F77_DBLE_CMPLX_ARG (work.fortran_vec ()),
                                     lwork, prwork, piwork, tmp_info));

          info = tmp_info;
          rank = tmp_rank;

          if (s.elem (0) == 0.0)
            rcon = 0.0;
          else
            rcon = s.elem (minmn - 1) / s.elem (0);

          retval.resize (n, nrhs);
        }
    }

  return retval;
}

ComplexColumnVector
ComplexMatrix::lssolve (const ColumnVector& b) const
{
  octave_idx_type info;
  octave_idx_type rank;
  double rcon;
  return lssolve (ComplexColumnVector (b), info, rank, rcon);
}

ComplexColumnVector
ComplexMatrix::lssolve (const ColumnVector& b, octave_idx_type& info) const
{
  octave_idx_type rank;
  double rcon;
  return lssolve (ComplexColumnVector (b), info, rank, rcon);
}

ComplexColumnVector
ComplexMatrix::lssolve (const ColumnVector& b, octave_idx_type& info,
                        octave_idx_type& rank) const
{
  double rcon;
  return lssolve (ComplexColumnVector (b), info, rank, rcon);
}

ComplexColumnVector
ComplexMatrix::lssolve (const ColumnVector& b, octave_idx_type& info,
                        octave_idx_type& rank, double& rcon) const
{
  return lssolve (ComplexColumnVector (b), info, rank, rcon);
}

ComplexColumnVector
ComplexMatrix::lssolve (const ComplexColumnVector& b) const
{
  octave_idx_type info;
  octave_idx_type rank;
  double rcon;
  return lssolve (b, info, rank, rcon);
}

ComplexColumnVector
ComplexMatrix::lssolve (const ComplexColumnVector& b,
                        octave_idx_type& info) const
{
  octave_idx_type rank;
  double rcon;
  return lssolve (b, info, rank, rcon);
}

ComplexColumnVector
ComplexMatrix::lssolve (const ComplexColumnVector& b, octave_idx_type& info,
                        octave_idx_type& rank) const
{
  double rcon;
  return lssolve (b, info, rank, rcon);

}

ComplexColumnVector
ComplexMatrix::lssolve (const ComplexColumnVector& b, octave_idx_type& info,
                        octave_idx_type& rank, double& rcon) const
{
  ComplexColumnVector retval;

  F77_INT nrhs = 1;

  F77_INT m = octave::to_f77_int (rows ());
  F77_INT n = octave::to_f77_int (cols ());

  F77_INT b_nel = octave::to_f77_int (b.numel ());

  if (m != b_nel)
    (*current_liboctave_error_handler)
      ("matrix dimension mismatch solution of linear equations");

  if (m == 0 || n == 0)
    retval = ComplexColumnVector (n, Complex (0.0, 0.0));
  else
    {
      volatile F77_INT minmn = (m < n ? m : n);
      F77_INT maxmn = (m > n ? m : n);
      rcon = -1.0;

      if (m != n)
        {
          retval = ComplexColumnVector (maxmn);

          for (F77_INT i = 0; i < m; i++)
            retval.elem (i) = b.elem (i);
        }
      else
        retval = b;

      ComplexMatrix atmp = *this;
      Complex *tmp_data = atmp.fortran_vec ();

      Complex *pretval = retval.fortran_vec ();
      Array<double> s (dim_vector (minmn, 1));
      double *ps = s.fortran_vec ();

      // Ask ZGELSD what the dimension of WORK should be.
      F77_INT lwork = -1;

      Array<Complex> work (dim_vector (1, 1));

      F77_INT smlsiz;
      F77_FUNC (xilaenv, XILAENV) (9, F77_CONST_CHAR_ARG2 ("ZGELSD", 6),
                                   F77_CONST_CHAR_ARG2 (" ", 1),
                                   0, 0, 0, 0, smlsiz
                                   F77_CHAR_ARG_LEN (6)
                                   F77_CHAR_ARG_LEN (1));

      // We compute the size of rwork and iwork because ZGELSD in
      // older versions of LAPACK does not return them on a query
      // call.
      double dminmn = static_cast<double> (minmn);
      double dsmlsizp1 = static_cast<double> (smlsiz+1);
      double tmp = octave::math::log2 (dminmn / dsmlsizp1);

      F77_INT nlvl = static_cast<F77_INT> (tmp) + 1;
      if (nlvl < 0)
        nlvl = 0;

      F77_INT lrwork = minmn*(10 + 2*smlsiz + 8*nlvl)
                       + 3*smlsiz*nrhs + (smlsiz+1)*(smlsiz+1);
      if (lrwork < 1)
        lrwork = 1;
      Array<double> rwork (dim_vector (lrwork, 1));
      double *prwork = rwork.fortran_vec ();

      F77_INT liwork = 3 * minmn * nlvl + 11 * minmn;
      if (liwork < 1)
        liwork = 1;
      Array<F77_INT> iwork (dim_vector (liwork, 1));
      F77_INT *piwork = iwork.fortran_vec ();

      F77_INT tmp_info = 0;
      F77_INT tmp_rank = 0;

      F77_XFCN (zgelsd, ZGELSD, (m, n, nrhs, F77_DBLE_CMPLX_ARG (tmp_data), m,
                                 F77_DBLE_CMPLX_ARG (pretval), maxmn,
                                 ps, rcon, tmp_rank, F77_DBLE_CMPLX_ARG (work.fortran_vec ()),
                                 lwork, prwork, piwork, tmp_info));

      info = tmp_info;
      rank = tmp_rank;

      lwork = static_cast<F77_INT> (std::real (work(0)));
      work.resize (dim_vector (lwork, 1));
      rwork.resize (dim_vector (static_cast<F77_INT> (rwork(0)), 1));
      iwork.resize (dim_vector (iwork(0), 1));

      F77_XFCN (zgelsd, ZGELSD, (m, n, nrhs, F77_DBLE_CMPLX_ARG (tmp_data), m,
                                 F77_DBLE_CMPLX_ARG (pretval),
                                 maxmn, ps, rcon, tmp_rank,
                                 F77_DBLE_CMPLX_ARG (work.fortran_vec ()), lwork,
                                 prwork, piwork, tmp_info));

      info = tmp_info;
      rank = tmp_rank;

      if (rank < minmn)
        {
          if (s.elem (0) == 0.0)
            rcon = 0.0;
          else
            rcon = s.elem (minmn - 1) / s.elem (0);

          retval.resize (n);
        }
    }

  return retval;
}

// column vector by row vector -> matrix operations

ComplexMatrix
operator * (const ColumnVector& v, const ComplexRowVector& a)
{
  ComplexColumnVector tmp (v);
  return tmp * a;
}

ComplexMatrix
operator * (const ComplexColumnVector& a, const RowVector& b)
{
  ComplexRowVector tmp (b);
  return a * tmp;
}

ComplexMatrix
operator * (const ComplexColumnVector& v, const ComplexRowVector& a)
{
  ComplexMatrix retval;

  F77_INT len = octave::to_f77_int (v.numel ());

  if (len != 0)
    {
      F77_INT a_len = octave::to_f77_int (a.numel ());

      retval = ComplexMatrix (len, a_len);
      Complex *c = retval.fortran_vec ();

      F77_XFCN (zgemm, ZGEMM, (F77_CONST_CHAR_ARG2 ("N", 1),
                               F77_CONST_CHAR_ARG2 ("N", 1),
                               len, a_len, 1, 1.0, F77_CONST_DBLE_CMPLX_ARG (v.data ()), len,
                               F77_CONST_DBLE_CMPLX_ARG (a.data ()), 1, 0.0, F77_DBLE_CMPLX_ARG (c), len
                               F77_CHAR_ARG_LEN (1)
                               F77_CHAR_ARG_LEN (1)));
    }

  return retval;
}

// matrix by diagonal matrix -> matrix operations

ComplexMatrix&
ComplexMatrix::operator += (const DiagMatrix& a)
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (nr != a_nr || nc != a_nc)
    octave::err_nonconformant ("operator +=", nr, nc, a_nr, a_nc);

  for (octave_idx_type i = 0; i < a.length (); i++)
    elem (i, i) += a.elem (i, i);

  return *this;
}

ComplexMatrix&
ComplexMatrix::operator -= (const DiagMatrix& a)
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (nr != a_nr || nc != a_nc)
    octave::err_nonconformant ("operator -=", nr, nc, a_nr, a_nc);

  for (octave_idx_type i = 0; i < a.length (); i++)
    elem (i, i) -= a.elem (i, i);

  return *this;
}

ComplexMatrix&
ComplexMatrix::operator += (const ComplexDiagMatrix& a)
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (nr != a_nr || nc != a_nc)
    octave::err_nonconformant ("operator +=", nr, nc, a_nr, a_nc);

  for (octave_idx_type i = 0; i < a.length (); i++)
    elem (i, i) += a.elem (i, i);

  return *this;
}

ComplexMatrix&
ComplexMatrix::operator -= (const ComplexDiagMatrix& a)
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (nr != a_nr || nc != a_nc)
    octave::err_nonconformant ("operator -=", nr, nc, a_nr, a_nc);

  for (octave_idx_type i = 0; i < a.length (); i++)
    elem (i, i) -= a.elem (i, i);

  return *this;
}

// matrix by matrix -> matrix operations

ComplexMatrix&
ComplexMatrix::operator += (const Matrix& a)
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (nr != a_nr || nc != a_nc)
    octave::err_nonconformant ("operator +=", nr, nc, a_nr, a_nc);

  if (nr == 0 || nc == 0)
    return *this;

  Complex *d = fortran_vec (); // Ensures only one reference to my privates!

  mx_inline_add2 (numel (), d, a.data ());
  return *this;
}

ComplexMatrix&
ComplexMatrix::operator -= (const Matrix& a)
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();

  if (nr != a_nr || nc != a_nc)
    octave::err_nonconformant ("operator -=", nr, nc, a_nr, a_nc);

  if (nr == 0 || nc == 0)
    return *this;

  Complex *d = fortran_vec (); // Ensures only one reference to my privates!

  mx_inline_sub2 (numel (), d, a.data ());
  return *this;
}

// other operations

boolMatrix
ComplexMatrix::all (int dim) const
{
  return ComplexNDArray::all (dim);
}

boolMatrix
ComplexMatrix::any (int dim) const
{
  return ComplexNDArray::any (dim);
}

ComplexMatrix
ComplexMatrix::cumprod (int dim) const
{
  return ComplexNDArray::cumprod (dim);
}

ComplexMatrix
ComplexMatrix::cumsum (int dim) const
{
  return ComplexNDArray::cumsum (dim);
}

ComplexMatrix
ComplexMatrix::prod (int dim) const
{
  return ComplexNDArray::prod (dim);
}

ComplexMatrix
ComplexMatrix::sum (int dim) const
{
  return ComplexNDArray::sum (dim);
}

ComplexMatrix
ComplexMatrix::sumsq (int dim) const
{
  return ComplexNDArray::sumsq (dim);
}

Matrix
ComplexMatrix::abs (void) const
{
  return ComplexNDArray::abs ();
}

ComplexMatrix
ComplexMatrix::diag (octave_idx_type k) const
{
  return ComplexNDArray::diag (k);
}

ComplexDiagMatrix
ComplexMatrix::diag (octave_idx_type m, octave_idx_type n) const
{
  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (nr != 1 && nc != 1)
    (*current_liboctave_error_handler) ("diag: expecting vector argument");

  return ComplexDiagMatrix (*this, m, n);
}

bool
ComplexMatrix::row_is_real_only (octave_idx_type i) const
{
  bool retval = true;

  octave_idx_type nc = columns ();

  for (octave_idx_type j = 0; j < nc; j++)
    {
      if (std::imag (elem (i, j)) != 0.0)
        {
          retval = false;
          break;
        }
    }

  return retval;
}

bool
ComplexMatrix::column_is_real_only (octave_idx_type j) const
{
  bool retval = true;

  octave_idx_type nr = rows ();

  for (octave_idx_type i = 0; i < nr; i++)
    {
      if (std::imag (elem (i, j)) != 0.0)
        {
          retval = false;
          break;
        }
    }

  return retval;
}

ComplexColumnVector
ComplexMatrix::row_min (void) const
{
  Array<octave_idx_type> dummy_idx;
  return row_min (dummy_idx);
}

ComplexColumnVector
ComplexMatrix::row_min (Array<octave_idx_type>& idx_arg) const
{
  ComplexColumnVector result;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (nr > 0 && nc > 0)
    {
      result.resize (nr);
      idx_arg.resize (dim_vector (nr, 1));

      for (octave_idx_type i = 0; i < nr; i++)
        {
          bool real_only = row_is_real_only (i);

          octave_idx_type idx_j;

          Complex tmp_min;

          double abs_min = octave::numeric_limits<double>::NaN ();

          for (idx_j = 0; idx_j < nc; idx_j++)
            {
              tmp_min = elem (i, idx_j);

              if (! octave::math::isnan (tmp_min))
                {
                  abs_min = (real_only ? tmp_min.real ()
                                       : std::abs (tmp_min));
                  break;
                }
            }

          for (octave_idx_type j = idx_j+1; j < nc; j++)
            {
              Complex tmp = elem (i, j);

              if (octave::math::isnan (tmp))
                continue;

              double abs_tmp = (real_only ? tmp.real () : std::abs (tmp));

              if (abs_tmp < abs_min)
                {
                  idx_j = j;
                  tmp_min = tmp;
                  abs_min = abs_tmp;
                }
            }

          if (octave::math::isnan (tmp_min))
            {
              result.elem (i) = Complex_NaN_result;
              idx_arg.elem (i) = 0;
            }
          else
            {
              result.elem (i) = tmp_min;
              idx_arg.elem (i) = idx_j;
            }
        }
    }

  return result;
}

ComplexColumnVector
ComplexMatrix::row_max (void) const
{
  Array<octave_idx_type> dummy_idx;
  return row_max (dummy_idx);
}

ComplexColumnVector
ComplexMatrix::row_max (Array<octave_idx_type>& idx_arg) const
{
  ComplexColumnVector result;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (nr > 0 && nc > 0)
    {
      result.resize (nr);
      idx_arg.resize (dim_vector (nr, 1));

      for (octave_idx_type i = 0; i < nr; i++)
        {
          bool real_only = row_is_real_only (i);

          octave_idx_type idx_j;

          Complex tmp_max;

          double abs_max = octave::numeric_limits<double>::NaN ();

          for (idx_j = 0; idx_j < nc; idx_j++)
            {
              tmp_max = elem (i, idx_j);

              if (! octave::math::isnan (tmp_max))
                {
                  abs_max = (real_only ? tmp_max.real ()
                                       : std::abs (tmp_max));
                  break;
                }
            }

          for (octave_idx_type j = idx_j+1; j < nc; j++)
            {
              Complex tmp = elem (i, j);

              if (octave::math::isnan (tmp))
                continue;

              double abs_tmp = (real_only ? tmp.real () : std::abs (tmp));

              if (abs_tmp > abs_max)
                {
                  idx_j = j;
                  tmp_max = tmp;
                  abs_max = abs_tmp;
                }
            }

          if (octave::math::isnan (tmp_max))
            {
              result.elem (i) = Complex_NaN_result;
              idx_arg.elem (i) = 0;
            }
          else
            {
              result.elem (i) = tmp_max;
              idx_arg.elem (i) = idx_j;
            }
        }
    }

  return result;
}

ComplexRowVector
ComplexMatrix::column_min (void) const
{
  Array<octave_idx_type> dummy_idx;
  return column_min (dummy_idx);
}

ComplexRowVector
ComplexMatrix::column_min (Array<octave_idx_type>& idx_arg) const
{
  ComplexRowVector result;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (nr > 0 && nc > 0)
    {
      result.resize (nc);
      idx_arg.resize (dim_vector (1, nc));

      for (octave_idx_type j = 0; j < nc; j++)
        {
          bool real_only = column_is_real_only (j);

          octave_idx_type idx_i;

          Complex tmp_min;

          double abs_min = octave::numeric_limits<double>::NaN ();

          for (idx_i = 0; idx_i < nr; idx_i++)
            {
              tmp_min = elem (idx_i, j);

              if (! octave::math::isnan (tmp_min))
                {
                  abs_min = (real_only ? tmp_min.real ()
                                       : std::abs (tmp_min));
                  break;
                }
            }

          for (octave_idx_type i = idx_i+1; i < nr; i++)
            {
              Complex tmp = elem (i, j);

              if (octave::math::isnan (tmp))
                continue;

              double abs_tmp = (real_only ? tmp.real () : std::abs (tmp));

              if (abs_tmp < abs_min)
                {
                  idx_i = i;
                  tmp_min = tmp;
                  abs_min = abs_tmp;
                }
            }

          if (octave::math::isnan (tmp_min))
            {
              result.elem (j) = Complex_NaN_result;
              idx_arg.elem (j) = 0;
            }
          else
            {
              result.elem (j) = tmp_min;
              idx_arg.elem (j) = idx_i;
            }
        }
    }

  return result;
}

ComplexRowVector
ComplexMatrix::column_max (void) const
{
  Array<octave_idx_type> dummy_idx;
  return column_max (dummy_idx);
}

ComplexRowVector
ComplexMatrix::column_max (Array<octave_idx_type>& idx_arg) const
{
  ComplexRowVector result;

  octave_idx_type nr = rows ();
  octave_idx_type nc = cols ();

  if (nr > 0 && nc > 0)
    {
      result.resize (nc);
      idx_arg.resize (dim_vector (1, nc));

      for (octave_idx_type j = 0; j < nc; j++)
        {
          bool real_only = column_is_real_only (j);

          octave_idx_type idx_i;

          Complex tmp_max;

          double abs_max = octave::numeric_limits<double>::NaN ();

          for (idx_i = 0; idx_i < nr; idx_i++)
            {
              tmp_max = elem (idx_i, j);

              if (! octave::math::isnan (tmp_max))
                {
                  abs_max = (real_only ? tmp_max.real ()
                                       : std::abs (tmp_max));
                  break;
                }
            }

          for (octave_idx_type i = idx_i+1; i < nr; i++)
            {
              Complex tmp = elem (i, j);

              if (octave::math::isnan (tmp))
                continue;

              double abs_tmp = (real_only ? tmp.real () : std::abs (tmp));

              if (abs_tmp > abs_max)
                {
                  idx_i = i;
                  tmp_max = tmp;
                  abs_max = abs_tmp;
                }
            }

          if (octave::math::isnan (tmp_max))
            {
              result.elem (j) = Complex_NaN_result;
              idx_arg.elem (j) = 0;
            }
          else
            {
              result.elem (j) = tmp_max;
              idx_arg.elem (j) = idx_i;
            }
        }
    }

  return result;
}

// i/o

std::ostream&
operator << (std::ostream& os, const ComplexMatrix& a)
{
  for (octave_idx_type i = 0; i < a.rows (); i++)
    {
      for (octave_idx_type j = 0; j < a.cols (); j++)
        {
          os << ' ';
          octave::write_value<Complex> (os, a.elem (i, j));
        }
      os << "\n";
    }
  return os;
}

std::istream&
operator >> (std::istream& is, ComplexMatrix& a)
{
  octave_idx_type nr = a.rows ();
  octave_idx_type nc = a.cols ();

  if (nr > 0 && nc > 0)
    {
      Complex tmp;
      for (octave_idx_type i = 0; i < nr; i++)
        for (octave_idx_type j = 0; j < nc; j++)
          {
            tmp = octave::read_value<Complex> (is);
            if (is)
              a.elem (i, j) = tmp;
            else
              return is;
          }
    }

  return is;
}

ComplexMatrix
Givens (const Complex& x, const Complex& y)
{
  double cc;
  Complex cs, temp_r;

  F77_FUNC (zlartg, ZLARTG) (F77_CONST_DBLE_CMPLX_ARG (&x),
                             F77_CONST_DBLE_CMPLX_ARG (&y),
                             cc,
                             F77_DBLE_CMPLX_ARG (&cs),
                             F77_DBLE_CMPLX_ARG (&temp_r));

  ComplexMatrix g (2, 2);

  g.elem (0, 0) = cc;
  g.elem (1, 1) = cc;
  g.elem (0, 1) = cs;
  g.elem (1, 0) = -conj (cs);

  return g;
}

ComplexMatrix
Sylvester (const ComplexMatrix& a, const ComplexMatrix& b,
           const ComplexMatrix& c)
{
  ComplexMatrix retval;

  // FIXME: need to check that a, b, and c are all the same size.

  // Compute Schur decompositions

  octave::math::schur<ComplexMatrix> as (a, "U");
  octave::math::schur<ComplexMatrix> bs (b, "U");

  // Transform c to new coordinates.

  ComplexMatrix ua = as.unitary_schur_matrix ();
  ComplexMatrix sch_a = as.schur_matrix ();

  ComplexMatrix ub = bs.unitary_schur_matrix ();
  ComplexMatrix sch_b = bs.schur_matrix ();

  ComplexMatrix cx = ua.hermitian () * c * ub;

  // Solve the sylvester equation, back-transform, and return the solution.

  F77_INT a_nr = octave::to_f77_int (a.rows ());
  F77_INT b_nr = octave::to_f77_int (b.rows ());

  double scale;
  F77_INT info;

  Complex *pa = sch_a.fortran_vec ();
  Complex *pb = sch_b.fortran_vec ();
  Complex *px = cx.fortran_vec ();

  F77_XFCN (ztrsyl, ZTRSYL, (F77_CONST_CHAR_ARG2 ("N", 1),
                             F77_CONST_CHAR_ARG2 ("N", 1),
                             1, a_nr, b_nr, F77_DBLE_CMPLX_ARG (pa), a_nr, F77_DBLE_CMPLX_ARG (pb),
                             b_nr, F77_DBLE_CMPLX_ARG (px), a_nr, scale, info
                             F77_CHAR_ARG_LEN (1)
                             F77_CHAR_ARG_LEN (1)));

  // FIXME: check info?

  retval = ua * cx * ub.hermitian ();

  return retval;
}

ComplexMatrix
operator * (const ComplexMatrix& m, const Matrix& a)
{
  if (m.columns () > std::min (m.rows (), a.columns ()) / 10)
    return ComplexMatrix (real (m) * a, imag (m) * a);
  else
    return m * ComplexMatrix (a);
}

ComplexMatrix
operator * (const Matrix& m, const ComplexMatrix& a)
{
  if (a.rows () > std::min (m.rows (), a.columns ()) / 10)
    return ComplexMatrix (m * real (a), m * imag (a));
  else
    return ComplexMatrix (m) * a;
}

/*

## Simple Dot Product, Matrix-Vector, and Matrix-Matrix Unit tests
%!assert ([1+i 2+i 3+i] * [ 4+i ; 5+i ; 6+i], 29+21i, 1e-14)
%!assert ([1+i 2+i ; 3+i 4+i ] * [5+i ; 6+i], [15 + 14i ; 37 + 18i], 1e-14)
%!assert ([1+i 2+i ; 3+i 4+i ] * [5+i 6+i ; 7+i 8+i], [17 + 15i 20 + 17i; 41 + 19i 48 + 21i], 1e-14)
%!assert ([1 i]*[i 0]', -i)

## Test some simple identities
%!shared M, cv, rv
%! M = randn (10,10) + i*rand (10,10);
%! cv = randn (10,1) + i*rand (10,1);
%! rv = randn (1,10) + i*rand (1,10);
%!assert ([M*cv,M*cv], M*[cv,cv], 1e-14)
%!assert ([M.'*cv,M.'*cv], M.'*[cv,cv], 1e-14)
%!assert ([M'*cv,M'*cv], M'*[cv,cv], 1e-14)
%!assert ([rv*M;rv*M], [rv;rv]*M, 1e-14)
%!assert ([rv*M.';rv*M.'], [rv;rv]*M.', 1e-14)
%!assert ([rv*M';rv*M'], [rv;rv]*M', 1e-14)
%!assert (2*rv*cv, [rv,rv]*[cv;cv], 2e-14)

*/

static inline char
get_blas_trans_arg (bool trans, bool conj)
{
  return trans ? (conj ? 'C' : 'T') : 'N';
}

// the general GEMM operation

ComplexMatrix
xgemm (const ComplexMatrix& a, const ComplexMatrix& b,
       blas_trans_type transa, blas_trans_type transb)
{
  ComplexMatrix retval;

  bool tra = transa != blas_no_trans;
  bool trb = transb != blas_no_trans;
  bool cja = transa == blas_conj_trans;
  bool cjb = transb == blas_conj_trans;

  F77_INT a_nr = octave::to_f77_int (tra ? a.cols () : a.rows ());
  F77_INT a_nc = octave::to_f77_int (tra ? a.rows () : a.cols ());

  F77_INT b_nr = octave::to_f77_int (trb ? b.cols () : b.rows ());
  F77_INT b_nc = octave::to_f77_int (trb ? b.rows () : b.cols ());

  if (a_nc != b_nr)
    octave::err_nonconformant ("operator *", a_nr, a_nc, b_nr, b_nc);

  if (a_nr == 0 || a_nc == 0 || b_nc == 0)
    retval = ComplexMatrix (a_nr, b_nc, 0.0);
  else if (a.data () == b.data () && a_nr == b_nc && tra != trb)
    {
      F77_INT lda = octave::to_f77_int (a.rows ());

      // FIXME: looking at the reference BLAS, it appears that it
      // should not be necessary to initialize the output matrix if
      // BETA is 0 in the call to ZHERK, but ATLAS appears to
      // use the result matrix before zeroing the elements.

      retval = ComplexMatrix (a_nr, b_nc, 0.0);
      Complex *c = retval.fortran_vec ();

      const char ctra = get_blas_trans_arg (tra, cja);
      if (cja || cjb)
        {
          F77_XFCN (zherk, ZHERK, (F77_CONST_CHAR_ARG2 ("U", 1),
                                   F77_CONST_CHAR_ARG2 (&ctra, 1),
                                   a_nr, a_nc, 1.0,
                                   F77_CONST_DBLE_CMPLX_ARG (a.data ()), lda, 0.0, F77_DBLE_CMPLX_ARG (c), a_nr
                                   F77_CHAR_ARG_LEN (1)
                                   F77_CHAR_ARG_LEN (1)));
          for (F77_INT j = 0; j < a_nr; j++)
            for (F77_INT i = 0; i < j; i++)
              retval.xelem (j, i) = octave::math::conj (retval.xelem (i, j));
        }
      else
        {
          F77_XFCN (zsyrk, ZSYRK, (F77_CONST_CHAR_ARG2 ("U", 1),
                                   F77_CONST_CHAR_ARG2 (&ctra, 1),
                                   a_nr, a_nc, 1.0,
                                   F77_CONST_DBLE_CMPLX_ARG (a.data ()), lda, 0.0, F77_DBLE_CMPLX_ARG (c), a_nr
                                   F77_CHAR_ARG_LEN (1)
                                   F77_CHAR_ARG_LEN (1)));
          for (F77_INT j = 0; j < a_nr; j++)
            for (F77_INT i = 0; i < j; i++)
              retval.xelem (j, i) = retval.xelem (i, j);

        }

    }
  else
    {
      F77_INT lda = octave::to_f77_int (a.rows ());
      F77_INT tda = octave::to_f77_int (a.cols ());
      F77_INT ldb = octave::to_f77_int (b.rows ());
      F77_INT tdb = octave::to_f77_int (b.cols ());

      retval = ComplexMatrix (a_nr, b_nc, 0.0);
      Complex *c = retval.fortran_vec ();

      if (b_nc == 1 && a_nr == 1)
        {
          if (cja == cjb)
            {
              F77_FUNC (xzdotu, XZDOTU) (a_nc, F77_CONST_DBLE_CMPLX_ARG (a.data ()), 1,
                                         F77_CONST_DBLE_CMPLX_ARG (b.data ()), 1,
                                         F77_DBLE_CMPLX_ARG (c));
              if (cja) *c = octave::math::conj (*c);
            }
          else if (cja)
            F77_FUNC (xzdotc, XZDOTC) (a_nc, F77_CONST_DBLE_CMPLX_ARG (a.data ()), 1,
                                       F77_CONST_DBLE_CMPLX_ARG (b.data ()), 1,
                                       F77_DBLE_CMPLX_ARG (c));
          else
            F77_FUNC (xzdotc, XZDOTC) (a_nc, F77_CONST_DBLE_CMPLX_ARG (b.data ()), 1,
                                       F77_CONST_DBLE_CMPLX_ARG (a.data ()), 1,
                                       F77_DBLE_CMPLX_ARG (c));
        }
      else if (b_nc == 1 && ! cjb)
        {
          const char ctra = get_blas_trans_arg (tra, cja);
          F77_XFCN (zgemv, ZGEMV, (F77_CONST_CHAR_ARG2 (&ctra, 1),
                                   lda, tda, 1.0,  F77_CONST_DBLE_CMPLX_ARG (a.data ()), lda,
                                   F77_CONST_DBLE_CMPLX_ARG (b.data ()), 1, 0.0, F77_DBLE_CMPLX_ARG (c), 1
                                   F77_CHAR_ARG_LEN (1)));
        }
      else if (a_nr == 1 && ! cja && ! cjb)
        {
          const char crevtrb = get_blas_trans_arg (! trb, cjb);
          F77_XFCN (zgemv, ZGEMV, (F77_CONST_CHAR_ARG2 (&crevtrb, 1),
                                   ldb, tdb, 1.0,  F77_CONST_DBLE_CMPLX_ARG (b.data ()), ldb,
                                   F77_CONST_DBLE_CMPLX_ARG (a.data ()), 1, 0.0, F77_DBLE_CMPLX_ARG (c), 1
                                   F77_CHAR_ARG_LEN (1)));
        }
      else
        {
          const char ctra = get_blas_trans_arg (tra, cja);
          const char ctrb = get_blas_trans_arg (trb, cjb);
          F77_XFCN (zgemm, ZGEMM, (F77_CONST_CHAR_ARG2 (&ctra, 1),
                                   F77_CONST_CHAR_ARG2 (&ctrb, 1),
                                   a_nr, b_nc, a_nc, 1.0, F77_CONST_DBLE_CMPLX_ARG (a.data ()),
                                   lda, F77_CONST_DBLE_CMPLX_ARG (b.data ()), ldb, 0.0, F77_DBLE_CMPLX_ARG (c),
                                   a_nr
                                   F77_CHAR_ARG_LEN (1)
                                   F77_CHAR_ARG_LEN (1)));
        }
    }

  return retval;
}

ComplexMatrix
operator * (const ComplexMatrix& a, const ComplexMatrix& b)
{
  return xgemm (a, b);
}

// FIXME: it would be nice to share code among the min/max functions below.

#define EMPTY_RETURN_CHECK(T)                   \
  if (nr == 0 || nc == 0)                       \
    return T (nr, nc);

ComplexMatrix
min (const Complex& c, const ComplexMatrix& m)
{
  octave_idx_type nr = m.rows ();
  octave_idx_type nc = m.columns ();

  EMPTY_RETURN_CHECK (ComplexMatrix);

  ComplexMatrix result (nr, nc);

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      {
        octave_quit ();
        result(i, j) = octave::math::min (c, m(i, j));
      }

  return result;
}

ComplexMatrix
min (const ComplexMatrix& m, const Complex& c)
{
  return min (c, m);
}

ComplexMatrix
min (const ComplexMatrix& a, const ComplexMatrix& b)
{
  octave_idx_type nr = a.rows ();
  octave_idx_type nc = a.columns ();

  if (nr != b.rows () || nc != b.columns ())
    (*current_liboctave_error_handler)
      ("two-arg min requires same size arguments");

  EMPTY_RETURN_CHECK (ComplexMatrix);

  ComplexMatrix result (nr, nc);

  for (octave_idx_type j = 0; j < nc; j++)
    {
      bool columns_are_real_only = true;
      for (octave_idx_type i = 0; i < nr; i++)
        {
          octave_quit ();
          if (std::imag (a(i, j)) != 0.0 || std::imag (b(i, j)) != 0.0)
            {
              columns_are_real_only = false;
              break;
            }
        }

      if (columns_are_real_only)
        {
          for (octave_idx_type i = 0; i < nr; i++)
            result(i, j) = octave::math::min (std::real (a(i, j)),
                                              std::real (b(i, j)));
        }
      else
        {
          for (octave_idx_type i = 0; i < nr; i++)
            {
              octave_quit ();
              result(i, j) = octave::math::min (a(i, j), b(i, j));
            }
        }
    }

  return result;
}

ComplexMatrix
max (const Complex& c, const ComplexMatrix& m)
{
  octave_idx_type nr = m.rows ();
  octave_idx_type nc = m.columns ();

  EMPTY_RETURN_CHECK (ComplexMatrix);

  ComplexMatrix result (nr, nc);

  for (octave_idx_type j = 0; j < nc; j++)
    for (octave_idx_type i = 0; i < nr; i++)
      {
        octave_quit ();
        result(i, j) = octave::math::max (c, m(i, j));
      }

  return result;
}

ComplexMatrix
max (const ComplexMatrix& m, const Complex& c)
{
  return max (c, m);
}

ComplexMatrix
max (const ComplexMatrix& a, const ComplexMatrix& b)
{
  octave_idx_type nr = a.rows ();
  octave_idx_type nc = a.columns ();

  if (nr != b.rows () || nc != b.columns ())
    (*current_liboctave_error_handler)
      ("two-arg max requires same size arguments");

  EMPTY_RETURN_CHECK (ComplexMatrix);

  ComplexMatrix result (nr, nc);

  for (octave_idx_type j = 0; j < nc; j++)
    {
      bool columns_are_real_only = true;
      for (octave_idx_type i = 0; i < nr; i++)
        {
          octave_quit ();
          if (std::imag (a(i, j)) != 0.0 || std::imag (b(i, j)) != 0.0)
            {
              columns_are_real_only = false;
              break;
            }
        }

      // FIXME: is it so much faster?
      if (columns_are_real_only)
        {
          for (octave_idx_type i = 0; i < nr; i++)
            {
              octave_quit ();
              result(i, j) = octave::math::max (std::real (a(i, j)),
                                                std::real (b(i, j)));
            }
        }
      else
        {
          for (octave_idx_type i = 0; i < nr; i++)
            {
              octave_quit ();
              result(i, j) = octave::math::max (a(i, j), b(i, j));
            }
        }
    }

  return result;
}

ComplexMatrix linspace (const ComplexColumnVector& x1,
                        const ComplexColumnVector& x2,
                        octave_idx_type n)
{
  octave_idx_type m = x1.numel ();

  if (x2.numel () != m)
    (*current_liboctave_error_handler)
      ("linspace: vectors must be of equal length");

  ComplexMatrix retval;

  if (n < 1)
    {
      retval.clear (m, 0);
      return retval;
    }

  retval.clear (m, n);
  for (octave_idx_type i = 0; i < m; i++)
    retval.xelem (i, 0) = x1(i);

  // The last column is unused so temporarily store delta there
  Complex *delta = &retval.xelem (0, n-1);
  for (octave_idx_type i = 0; i < m; i++)
    delta[i] = (x1(i) == x2(i)) ? 0 : (x2(i) - x1(i)) / (n - 1.0);

  for (octave_idx_type j = 1; j < n-1; j++)
    for (octave_idx_type i = 0; i < m; i++)
      retval.xelem (i, j) = x1(i) + static_cast<double> (j)*delta[i];

  for (octave_idx_type i = 0; i < m; i++)
    retval.xelem (i, n-1) = x2(i);

  return retval;
}

MS_CMP_OPS (ComplexMatrix, Complex)
MS_BOOL_OPS (ComplexMatrix, Complex)

SM_CMP_OPS (Complex, ComplexMatrix)
SM_BOOL_OPS (Complex, ComplexMatrix)

MM_CMP_OPS (ComplexMatrix, ComplexMatrix)
MM_BOOL_OPS (ComplexMatrix, ComplexMatrix)